In situ Plating And Soldering Of Materials Covered With A Surface Film

ABSTRACT

The disclosed subject matter provides systems and methods for etching and/or metal plating of substrate materials. An exemplary method in accordance with the disclosed subject matter for metal-plating or etching a substrate includes submerging portions of the substrate in a first bath of chemical solution, performing in-situ laser ablation of the substrate to achieve an immersion plated pattern with a first cation, plating-up the immersion plated pattern with the first cation in the first bath, and plating-up the immersion plated pattern with a second cation in a second bath. The same or another exemplary method can utilize a reel-to-reel system. The plating-up can begin after patterning by immersion plating is complete. Further, a single plating pattern can be used to define a pattern and the same bath can be used to plate the immersion pattern, thereby achieving a uniform thickness of the pattern.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/041,630, filed Apr. 2, 2008, U.S. Provisional Application No.61/078,596, filed Jul. 7, 2008, U.S. Provisional Application No.61/117,499, filed Nov. 24, 2008 and U.S. Application No. 61/119,535,filed Dec. 3, 2008, each of which is incorporated by reference in theirentirety herein, and from which priority is claimed.

FIELD

The present application relates to systems and methods for metal platingand etching of substrates. More particularly, the application relates tometal plating, soldering and etching of readily oxidizable substrates orother substrates with thin layers that inhibit metal plating.

BACKGROUND

Metal plating of articles or base substrates is a common industrialpractice. A metal layer can be coated or plated on the surface of anarticle, for example, for decoration, reflection of light, protectionagainst corrosion, or increased wearing quality. Articles or basesubstrates, which are made of metal or non-metallic material, can beplated with suitable coating metals using techniques such aselectroplating, electroless plating, metal spraying, hot dipgalvanizing, vacuum metallization or other available processes.

Plating by electrolysis, or electroplating, is a commonly used techniquefor metal plating because it permits the control of the thickness of theplating. Cadmium, zinc, silver, gold, tin, copper, nickel, and chromiumare commonly used plating/coating metals. In immersion or electrolessplating, some metals are directly precipitated, without electricity,from chemical solutions onto the surface of the substrates. Thesilvering of mirrors is a type of plating in which silver isprecipitated chemically on glass. Any of the common metals and somenonmetals, e.g., plastics, with suitably prepared (e.g., etched)surfaces can be used as the article or base substrate material.

However, some metals (e.g., aluminum and refractory metals liketungsten, tantalum and molybdenum), which have desirable physical orstructural properties for use as base substrate material, are extremelydifficult to plate by simple immersion plating or electroplatingtechniques. The difficulty in plating these metals can, for example, berelated to the propensity of these metals to oxidize in air, as a resultof which an interfering metal-oxide or insulating layer forms on anyexposed or etched surface of these metals. The interfering metal-oxideor insulating layer hinders reduction of metal ions, which is requiredfor metal plating. Therefore, techniques for metal platingreadily-oxidizable materials (such as tungsten, tantalum and aluminum)commonly involve a number of expensive and tedious substrate preparationsteps, which are designed to avoid or inhibit the formation of surfacelayers which can interfere with the plating processes. For example, acommon technique for metal plating onto an aluminum substrate involvesfirst zincating and then gold plating the aluminum substrate prior toplating the aluminum substrate with a metal of choice. For substrates orarticles made from refractory metals such as tantalum and tungsten, thesubstrate preparation steps prior to metal plating often involvecumbersome high temperature processing steps.

The interfering surface oxide layers formed on these readily-oxidizablemetals also hinders etching of the surface of these metals, which can benecessary prior to any substrate preparation steps themselves. Thesurface oxide layer coating inhibits the dissolution of the metal underconventional etching conditions. Again, a number of fairly harsh stepsare required to prepare the substrate surfaces for etching. See e.g.,Modern Electroplating (3rd edition), F. Lowenheim, Ed. John Wiley & SonsInc. (1974), pp. 591-625, which is hereby incorporated by reference inits entirety. Further discussion of electroless plating of commonmaterials that require multistep processing to achieve metal plating dueto presence of interfering surface films can, for example, be found, inElectroless Plating: Fundamentals and Applications, Glenn O. Mallory andJuan B. Hajdu, Eds. American Electroplaters and Surface FinishersSociety (1990), pp. 193-204, also incorporated by reference herein.

There remains a need to improve metal plating, soldering and etching ofsubstrates, including simplifying techniques for metal plating ofsubstrates having awkward surface geometries (e.g., cylindrical,non-planar or enclosed surfaces) which are prone to having interferingsurface films form, for example, during conventional metal plating,soldering and etching processes or steps. Further, there remains a needto improve substrate preparation techniques (e.g., removal of native orpreformed surface oxide layers) prior to plating or etching action.

SUMMARY

The disclosed subject matter provides systems and methods for etchingand/or metal plating of substrate materials, including but not limitedto, use of light sources (e.g. laser beams) for in situ surfaceconditioning of hard to plate substrates (e.g. aluminum, which is hardto plate due to readily forming inhibiting surface layers (e.g., anatural surface oxide)).

In one exemplary embodiment, a surface (e.g. an aluminum surface) isplated by directing focused light (e.g. a laser) onto the surfacethrough a plating electrolyte (e.g., a copper sulfate solution) while atthe same time applying a fixed negative voltage to the surface withrespect to a counter electrode. In one embodiment, the electrolyte isrelatively transmissive to the light source (e.g. laser light).

Another exemplary method in accordance with the disclosed subject matterfor metal-plating or etching a substrate includes submerging portions ofthe substrate in a first bath of chemical solution, laser ablating thesubstrate (e.g. laser ablating a thin layer of the surface of thesubstrate) to achieve an immersion plated pattern with a first cation,plating-up the immersion plated pattern with the first cation in thefirst or second bath, and plating-up the immersion plated pattern with asecond cation in a second bath. The same, or other exemplary methods canutilize a reel-to-reel system. The plating-up can begin after patterningis complete. Further, a single plating pattern can be used to define apattern and the same bath can be used to plate the immersion pattern,thereby achieving a uniform thickness of the pattern.

An exemplary method utilizing a reel-to-reel system can further includeusing a scanning mirror in combination with the movement of thesubstrate located on one of two or more reels. Further the scanningmirror can be controlled by a processing unit programmed to have aprescribed pattern that results in distributing a beam spatially, whilestill contacting the substrate passing though a chemical solution.

An exemplary system in accordance with the disclosed subject matter formetal-plating or etching a substrate that includes a laser, a first bathincluding a first chemical solution and a first counter electrode andcoupled to a first power supply utilizing a switch for producingmechanical motion of the substrate, and a second bath including a secondchemical solution and the first counter electrode and coupled to asecond power supply.

Another exemplary system in accordance with the disclosed subject matterprovides a system for metal-plating or etching a substrate that includesa bath, and a scanning mirror coupled to a lens and a laser for ablatingthe substrate (e.g. ablating a thin layer of the surface of thesubstrate) in the bath to achieve the plating or etching. A reel-to-reelsystem can be utilized to control the movement of the substrate.

Another exemplary method in accordance with the disclosed subject matterincludes depositing a chemical solution layer on a surface of thesubstrate, and laser ablating the substrate through the chemicalsolution layer to achieve the plating or etching. The same or anotherexemplary method can irradiate the substrate, for example, by passing alaser beam emitted from the laser through a lens. The lens can be, forexample, a lens with a focal length greater than about 30 centimeters.The same or another embodiment can utilize a reel-to-reel system. Incertain embodiments, the depositing of the chemical solution layer on asurface of the substrate can include depositing the chemical solutionlayer on two surfaces of the substrate. In the same or anotherembodiment, the laser ablating of the substrate can be performedutilizing a plurality of mirrors to laser ablate the substrate from morethan one angle simultaneously.

An exemplary system for metal-plating or etching a substrate includes afirst bath, a supply tank for depositing a layer of chemical solutiononto a surface of the substrate, and a laser optically coupled to a lensfor ablating the surface of the substrate in the first bath to achieveplating or etching. The same or another exemplary system can use areel-to-reel system to control the movement of the substrate. The sameor another embodiment, the system can further include a second bathseparated from the first bath by a first partition, the second bathcontaining an electrode for electroplating the substrate. In oneembodiment, the supply tank can be the first bath. In the same oranother embodiment, the system can further include a second partition,positioned adjacent to a wall of the first bath such that a channel isformed in which the layer of chemical solution is deposited onto twosurfaces of the substrate. The system can further include a plurality ofmirrors for directing a laser beam produced by the laser to irradiatethe substrate surface from more than one angle.

Another exemplary method for metal-plating or etching a substrate frommore than one angle simultaneously includes submerging portions of thesubstrate in a first bath of chemical solution, and laser ablating thesurface of the substrate using a plurality of mirrors to irradiate thesubstrate from two or more angles to achieve the plating or etching.This method can further include plating-up the substrate with a cationin the first bath. In the same or another embodiment, this method canfurther include transferring the substrate to a second bath, andplating-up the substrate with a cation in the second bath. In oneembodiment, a single laser is used to perform said in-situ laserimmersion plating. In an alternative embodiment, two lasers are used toperform said in-situ laser immersion plating.

An exemplary system for metal-plating or etching a substrate (e.g. anawkward, non-planar (i.e., curved or cylindrical), or enclosed platingsurface) from more than one angle simultaneously includes a bathcontaining a chemical solution, at least one lens, and at least onelight source (e.g. laser) coupled to a plurality of mirrors forirradiating the substrate from more than one angle simultaneously withlaser beams passed through the lens or lenses. For example, one or more(e.g. a set of) optical elements is used to direct laser light ontosubstrates having awkward non-planar (i.e., curved or cylindrical), orenclosed plating surfaces.

For example, in one embodiment one or more optical elements (e.g.semitransparent and totally reflecting mirrors) is used to irradiate all360 degrees of an aluminum wire substrate circumference as the wire isdrawn from one reel to a second windup reel through the electrolyte.Other optical elements (e.g., spherical bi-convex, planar convex, orcylindrical lenses) can be used to focus the light on the substrate.Alternatively, the laser light can be directed onto the wire substrateby way of an optical fiber (light pipe). The tip of the fiber can extendinto the electrolyte or be otherwise externally positioned to direct thelight into the electrolyte. A focusing lens can be positioned at the tipof the fiber as needed to focus the light on the substrate. In oneembodiment, semistransparent mirrors refer to mirrors that transmitsbetween 25-50% of incoming light.

An optical fiber (light pipe) can also be used for in situ plating ofthe inside of a tube-shaped substrate (e.g., aluminum tubing), which isimmersed in the electrolyte. The optical fiber (light pipe) extends intothe tubing and directs laser light onto plating surfaces on the insidewall of the tubing. The optical fiber and/or the tubing substrate alsocan be attached to a mechanical rotational and translational mechanism.The light pipe and the tubing can be moved laterally while rotating sothat the entire inside of the tubing surface is irradiated. A lens canbe positioned at the end of the optical fiber to focus the light ontothe inside of the tubing wall.

The aforementioned plating methods allow aluminum to be soldered afterplating a small amount of copper. Without the copper plating, aluminumgenerally cannot be soldered. However, other metals such as nickel,chrome, silver and the like can also be plated in situ on the aluminumby means of the laser in order to allow soldering of the aluminum.

Further, the aforementioned plating methods can allow substrates (e.g.,aluminum) to be soldered by direct plating of a soldering material ontothe substrate without any intermediate layer (e.g., copper).

In another embodiment, aluminum wires can be plated with a copperoverlayer. Such Al—Cu composite wires can be advantageously used forhigh frequency transmission lines. At sufficiently high frequencies, theskin depth effect will cause the high frequency current to be carried bythe copper overlayer. Thus, the aluminum, which is much less expensivethan copper, can be used as the central core of the wire, while arelatively thin layer of copper plated onto the aluminum, with higherelectrical conductivity, carries the current. This particular embodimentachieves reduction in cost, as compared to a pure copper wire.

Other embodiments of the present application provide methods and systemsfor in situ oxide removal from the surface of metals to be plated (orremoval of other inhibiting films from the metals) by means of a UV orfemtosecond set of laser pulses. In certain embodiments, the metal iseither immersed in the solution in which plating or etching is to occur,or the oxide is covered with a film of solution (e.g on the order of 0.1to 1 mm) through which the laser can readily penetrate to remove theoxide. After the oxide ablation, the sample is removed to the solution(preferably rapidly removed) in which plating (or etching) is to occur.In either case, the substrate to be plated or etched is in solutionduring ablation. In an alternate embodiment, the substrate from whichthe oxide is to be removed is immersed in an inert gas during the laserablation processing by the femtosecond or UV laser, after which it isquickly transferred and immersed into an etching or plating solution foretching or plating respectively. In yet another embodiment, the laserprocessing can take place in a first electrolyte, then transferred to asecond electrolyte for plating or etching.

Other embodiments of the present application provide methods and systemsto prevent unwanted depositions in areas not subjected to the laserenergy by introducing a source of steam in the reel to reel platingsystem to cause oxidation. For example, certain embodiments employsteam, incident on the surface of the Al or other oxide coated metal tobe plated, to increase the thickness of the natural oxide coating. Thelaser fluence for removing the oxide is then adjusted to enable removalof the thicker oxide in designated areas on the metal to beplated/etched while at the same time preventing unwanted depositions inareas not subjected to the laser oxide removal source (e.g. a laser).

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the disclosed subject matter, its nature, andvarious advantages will be more apparent from the following detaileddescription of the preferred embodiments and the accompanying drawings,wherein like reference characters represent like elements throughout,and in which:

FIG. 1 is a schematic illustration of a plating/etching cell with anexemplary arrangement of optical elements for laser-assisted in-situsurface conditioning of wire substrates, in accordance with theprinciples of the disclosed subject matter.

FIG. 2 is a schematic illustration of a plating/etching cell withanother exemplary arrangement of optical elements for laser-assistedin-situ surface conditioning of wire substrates, in accordance with theprinciples of the subject matter disclosed herein.

FIG. 3 is a schematic illustration of a plating/etching cell with anexemplary arrangement of optical elements for laser-assisted in-situsurface conditioning of substrates with enclosed surfaces, in accordancewith the principles of the subject matter disclosed herein.

FIG. 4 is a schematic illustration of a plating/etching cell with anexemplary arrangement of optical elements for laser-assisted in-situsurface conditioning of substrates for two-dimensional reel-to-reelplating/etching, in accordance with the principles of the subject matterdisclosed herein.

FIG. 5 is a schematic illustration of another plating/etching cell withan exemplary arrangement of optical elements and substrate movementmechanisms for laser-assisted in-situ surface conditioning of substratesfor two-dimensional plating/etching, in accordance with the principlesof the subject matter disclosed herein.

FIGS. 6 and 7 are schematic illustrations of processes for solderingaluminum substrates, in accordance with the principles of the subjectmatter disclosed herein.

FIG. 8 illustrates a set of scanning mirrors that enable 2- and3-dimensional plating on an oxide coated substrate, in accordance withthe principles of the subject matter disclosed herein.

FIG. 9 a is a schematic illustration of an exemplary plating/etchingcell arrangement, which is configured for removing an interferinginsulating surface film by in situ resistive heat treatment just priorto or during the metal plating or etching of a subject substrate, inaccordance with the principles of the disclosed subject matter. The cellis provided with a counter electrode and pump for circulating anelectrolyte or etchant.

FIG. 9 b schematically illustrates details of exemplary electricalcontacts and the electrode support structures for the cell arrangementof FIG. 9 a, in accordance with the principles of the disclosed subjectmatter.

FIG. 10 is a schematic illustration of another exemplary plating/etchingcell arrangement, which is configured for removal of an interferinginsulating surface film by laser light treatment just prior to or duringthe metal plating or etching of a subject substrate, in accordance withthe principles of the disclosed subject matter. The plating/etching cellarrangement includes a moveable holder for moving the substrate relativeto the laser light so that different surface portions of the substratecan be treated sequentially.

FIG. 11 is a schematic illustration of yet another exemplaryplating/etching cell arrangement, which is configured for in situremoval of an interfering insulating surface film by mechanicaltreatment during the metal plating or etching of a subject substrate, inaccordance with the principles of the disclosed subject matter. Theplating/etching cell arrangement includes a scratching or scraping toolfor mechanically removing the interfering insulating film from thesubstrate while the substrate is at least partially submerged in anelectrolyte or other plating/etching fluid.

FIG. 12 is a schematic illustration of the plating cell arrangement ofFIG. 11, which has been additionally configured to apply heat to thesubstrate facing away from the counter electrode, in accordance with theprinciples of the disclosed subject matter.

FIG. 13 is a schematic illustration of an exemplary plating/etching cellarrangement, which is configured for removal of an interfering surfacefilm on a wire substrate by in situ mechanical stripping during metalplating or etching of the wire substrate, in accordance with theprinciples of the disclosed subject matter. The wire substrate, whichcan be supplied and picked up in a reel-to-reel arrangement, is passedthough a knife-edge die which strips the interfering surface film, whilesubmerged in an electrolyte or other plating/etching fluid.

FIG. 14 is a schematic illustration of another exemplary plating/etchingcell arrangement, which is configured for in situ mechanical strippingof an interfering film on flat stock substrate during metal plating oretching of the flat stock substrate, in accordance with the principlesof the disclosed subject matter. The flat stock substrate is passedthough a knife-edge die, which strips the interfering surface film,while the flat stock substrate is submerged in an electrolyte or otherplating/etching fluid.

FIG. 15 is a schematic illustration of a metal-plated article made froma refractory metal substrate in which the metal plating layer is bondeddirectly to the substrate material without any intervening substratemodification or seed layers, in accordance with the principles of thedisclosed subject matter.

FIG. 16 a is a schematic illustration of an exemplary plating/etchingcell arrangement including a coating-removal enclosure in whichinhibiting surface films are mechanically removed from substratesurfaces prior to immersion in a plating or etching bath, in accordancewith the principles of the disclosed subject matter. The coating-removalenclosure can be supplied with an inert or reducing gas atmosphere, andis compatible with reel-to-reel substrate supply and pick-uparrangements.

FIG. 16 b is a schematic illustration of another exemplaryplating/etching cell arrangement including a coating-removal enclosurein which substrates are electrically heated in an inert or reducingambient to remove inhibiting surface films prior to immersion in aplating or etching bath, in accordance with the principles of thedisclosed subject matter. Like the coating-removal enclosure of FIG. 16a, the enclosure of FIG. 16 b is compatible with reel-to-reel substratesupply and pick-up arrangements.

FIG. 16 c is a schematic illustration of yet another exemplaryplating/etching cell arrangement including a coating-removal enclosurein which a substrate is laser irradiated in an inert or reducing ambientto remove inhibiting surface films prior to immersion in a plating oretching bath, in accordance with the principles of the disclosed subjectmatter. Like the coating-removal enclosures of FIGS. 16 a and 16 b, theenclosure of FIG. 16 c is compatible with reel-to-reel substrate supplyand pick-up arrangements.

FIG. 16 d is a schematic illustration of an exemplary plating/etchingcell arrangement in which inhibiting surface films are mechanicallyremoved from the substrate surfaces in air prior to immersion in aplating or etching bath, in accordance with the principles of thedisclosed subject matter. The cell arrangement is configured with areel-to-reel substrate supply and pick-up arrangement.

FIG. 17 is a schematic illustration of still another exemplaryplating/etching cell arrangement including a coating-removal enclosurein which a substrate can be treated to remove inhibiting surface filmsprior to immersion in a plating or etching bath, in accordance with theprinciples of the disclosed subject matter. The coating removalenclosure is mounted directly above the plating/etching bath and can beconfigured to treat individual substrate pieces one by one, or to treata continuous reel-to-reel supply of substrates.

FIG. 18 is a schematic illustration of a composite substrate, which canbe plated or etched in accordance with the principles of the disclosedsubject matter. The composite substrate has an outer material layersupported on a base substrate. The outer layer is coated with aninhibiting coating film which is removed prior to plating or etching ofthe composite substrate.

FIG. 19 is a schematic illustration of an exemplary plating/etching cellarrangement, which is configured for removal of an interferinginsulating surface film by induction heating or microwave irradiationjust prior to metal plating or etching of a subject substrate, inaccordance with the principles of the disclosed subject matter.

FIG. 20 is a schematic illustration of an exemplary induction heatingarrangement, which can be used to remove inhibiting surface films onsubstrates with trenched surface topography such as silicon substratewafers, in accordance with the principles of the disclosed subjectmatter.

FIG. 21 is a schematic illustration of another arrangement, in which anion beam is used to remove inhibiting surface films on substrates withtrenched surface topography such as silicon substrate wafers, inaccordance with the principles of the disclosed subject matter.

FIG. 22 is a schematic illustration of an exemplary reel-to-reelplating/etching cell arrangement having a substrate preparation chamberin which induction heating or magnetron radiation is used for removal ofinterfering surface films, in accordance with the principles of thedisclosed subject matter.

FIG. 23 is a schematic illustration of a stamping press, which is usedto prepare shaped substrates in an oxide-layer free condition suitablefor plating or etching action, in accordance with the principles of thedisclosed subject matter.

FIGS. 24 and 25 are schematic illustrations of exemplary plating/etchingcell arrangements in which separate tanks are provided for removal ofinterfering insulating surface films on a substrate and for plating thesubstrate, in accordance with the principles of the disclosed subjectmatter.

FIG. 26 is a schematic illustration of another exemplary plating/etchingcell arrangement for obtaining electrolytic plating or etching ofindividual substrates having inhibiting surface films, in accordancewith the principles of the disclosed subject matter. The plating/etchingcell is configured so that a high voltage pulse (or a series of pulses)is applied to the substrate (e.g. 20-200 V, depending on size of thesubstrate) to remove the interfering inhibiting surface films and then alow voltage signal (e.g. 2-3 V for a substrate of 5×5 cm), which can bea cw or a modulated cw signal, is applied to activate the desiredplating and/or etching processes.

FIG. 27 is a schematic illustration of yet another exemplaryplating/etching cell arrangement for obtaining electrolytic plating oretching of long wire or flat sheet stock substrates having inhibitingsurface films, in accordance with the principles of the disclosedsubject matter. The plating/etching cell arrangement includes areel-to-reel material handling system. Like the plating/etching cellarrangement of FIG. 26, the plating/etching cell is configured so that ahigh voltage pulse can be applied to the substrate to remove theinterfering or inhibiting surface films, and then a low voltage signalcan be applied to activate the desired plating and/or etching processes.

FIGS. 28 and 29 are schematic illustrations of the alternating highvoltage and low voltage pulses that can be used in electroplating oretching processes in the cell arrangements of FIGS. 26 and 27,respectively.

FIG. 30 is a schematic illustration of still another exemplaryplating/etching cell arrangement for obtaining electrolytic plating oretching of substrates having inhibiting surface films, in accordancewith the principles of the disclosed subject matter. The plating/etchingcell arrangement employs an electrolyte jet to co-linearly guide a highintensity laser beam for removal of the inhibiting surface films.

FIG. 31 is a schematic illustration of a further exemplaryplating/etching cell arrangement for obtaining electrolytic plating oretching of substrates having inhibiting surface films, in accordancewith the principles of the disclosed subject matter. The plating/etchingcell arrangement uses a high intensity laser beam for removal of theinhibiting surface films for substrate surface portions under a definedvolume of electrolyte.

FIG. 32 is a schematic illustration of a sample which a contactpatterning mask disposed thereon. The contact mask can be a positive ornegative photo resist layer which patterned using photolithography.Plating and/or etching of the substrate occurs in the pattern openingsfrom which inhibiting surface coatings are removed by the in-situremoval techniques of the disclosed subject matter.

FIG. 33 a is a schematic illustration of the voltage pulse appliedbetween the counter electrode and the substrate of FIG. 32 while thelatter is immersed in an electrolyte cell (FIG. 33 b) in order to removeinhibiting surface coatings from the substrate surface in the patternopening regions, in accordance with the principles of the disclosedsubject matter.

FIG. 34 is a schematic illustration of the electrolyte cell of FIG. 25 bnow used to apply a small voltage for the purpose of plating or etchingthe substrate surface in the pattern opening regions from whichinhibiting oxide layers have been removed by application of the voltagepulse of FIG. 33 a.

FIG. 35 is a schematic illustration of a metal-plating or etching systemin accordance with an embodiment of the disclosed subject matter.

FIG. 36 is a schematic illustration of a metal-plating or etching systemutilizing a reel-to-reel system in accordance with an embodiment of thedisclosed subject matter.

FIG. 37 is a schematic illustration of a metal-plating or etching systemutilizing a two bath reel-to-reel system and an electrolyte layeringsystem in conjunction with a laser and lens system in accordance with anembodiment of the disclosed subject matter.

FIG. 38 is a perspective view of a sample wire with arrow depicting thelaser light directed onto the wire from four directions and a fiftharrow depicting the direction of travel of the wire in accordance withan embodiment of the disclosed subject matter.

FIG. 39 is a schematic illustration of a system for four sided oxideablation of a wire sample using a single laser to achieve immersionplating in accordance with an embodiment of the disclosed subjectmatter.

FIG. 40 is a schematic illustration of a system for four sided oxideablation of a wire sample using two lasers to achieve immersion platingin accordance with an embodiment of the disclosed subject matter.

FIG. 41 illustrates a side perspective view of a reel-to-reel system inaccordance with the embodiments of FIGS. 39 and 40.

FIG. 42 is a schematic illustration of a system and method for two sidedoxide ablation of a ribbon or wire sample using a single laser toachieve immersion plating and/or maskless-etching using a single laser.

FIG. 43 illustrates a side view showing the feeding of the sample of theabove embodiment into the channel formed by the two partitions.

FIG. 44 is a typical set-up for in situ plating using one of a UV orfemtosecond laser for oxide removal. In certain embodiments, oxideremoval is followed by immediate plating unless immersion plating hasoccurred during or immediately following ablation.

FIG. 45 is a set of spectrophotometric curves showing the transmissionpercentages for water, a standard copper sulfate plating solution, and aWatts bath for nickel plating using a 1 cm deep cuvette.

FIG. 46 is a set of spectrophotometric curves for Technic™ platingsolutions of silver, gold and tin.

FIG. 47 is a transmission curve for a 1.8 M solution of sulfuric acid.

FIG. 48 is an exemplary arrangement where ablation is performed byeither a UV or femtosecond laser occurs in an inert gas, slightly overpressured, followed by transferal of the oxide free material to aplating or etching bath.

DETAILED DESCRIPTION

The disclosed subject matter provides systems and methods for metalplating, soldering and etching of substrate materials which have awkwardgeometries (e.g., cylindrical outer surfaces, inside tube surfaces).

International Published Patent Application No. WO 2006/086407, which ishereby incorporated by reference, discloses systems and methods forplating and/or etching of hard-to-plate metals (e.g., aluminum andrefractory metals like tungsten, tantalum and molybdenum) which havedesirable physical or structural properties for use as base substratematerial, but are extremely difficult to plate by simple immersionplating or electroplating techniques. The difficulty in plating thesemetals can, for example, be related to their propensity to oxidize inair, as a result of which an interfering metal-oxide or insulating layerforms on any exposed or etched surface of these metals. The interferingmetal-oxide or insulating layer hinders reduction of metal ions, whichis required to cause metal plating. The systems and methods described inthe aforementioned patent application are designed to overcome thedeleterious effect of superficial coating or oxide layers that interferewith the plating or etching of certain metal substrates. The systems andmethods involve in situ removal of coating materials from the surfacesof the metal substrates while the substrates are either submerged inplating or etching solutions, or are positioned in a proximate enclosurejust prior to submersion in the plating or etching solutions. This insitu removal of coating layers can be achieved by pulse heating orphotoablation of the substrate and the inhibiting coating layers.Electrical energy or laser light energy can be used for this purpose.

Like the systems and methods described in International PatentApplication No. PCT/US06/04329 for plating substrates that are usuallycoated with interfering thin surface films, the systems and methodsdescribed herein employ in situ techniques to remove or inhibit theinterfering thin surface film on the substrate surfaces, even if thelatter have awkward geometries.

The in situ removal techniques can exploit optical energy absorption toremove or inhibit the interfering thin surface films on substrate worksurfaces before metal plating, etching or solder deposition. An energybeam, which is generated by a suitable optical source (e.g., a laser),is directed onto the surface of a substrate. Optical absorption of thedirected energy beam can lead to localized heating and/orphotodecomposition (also known as ablative photodecomposition) of theinterfering thin surface films.

The systems and methods of the disclosed subject matter are describedherein with reference to aluminum (e.g., Al wire) as an exemplaryhard-to-plate substrate material. Aluminum is of widespread industrialinterest because of its high electrical conductivity and itscomparatively low cost vis-à-vis copper for similar applications (e.g.,for electricity transmission). However, aluminum is difficult to plateor solder using conventional electroplating/soldering methods. Thesystems and methods described herein enable plating, soldering and/oretching of aluminum and other hard-to-plate metals without requiring theconventional multiple surface pre-conditioning steps that include theuse of very harsh chemicals (e.g., HF). Aluminum can be plated simply bydirecting focused light onto the substrate surfaces disposed in anelectroplating cell. The light is focused onto the substrate surfacethrough the electroplating solution (e.g., copper sulfate).

FIG. 1 schematically shows a method for plating onto acylindrically-shaped Al wire 110, using one or more or more focusedlasers or laser beams for surface preparation. Wire 110 is drawncontinuously through an electroplating tank or cell (not shown). Theelectroplating tank or cell can be similar to the cells or tanksdescribed in PCT International Application No. PCT/US06/04329 havingcontinuous raw stock feed and pick-up mechanisms (e.g., reel-to-reelmaterial handling systems). In situ preparation of Al wire 110 (i.e.,removal or inhibition of interfering surface films) for electroplatingis achieved by directing a laser beam 120 onto all of the circumferenceof wire 110 as it is drawn through the electroplating solution.

Laser beam 120, which can be generated by a CW or pulsed laser 130, isdirected to be incident on the circumference of wire 110 from multipledirections (e.g., all directions, 360 degrees) by a suitable opticalarrangement 140. As shown in FIG. 1, exemplary optical arrangement 140includes a semi-transparent mirror 140A and three totally reflectingmirrors 140B in a quadrilateral configuration. Semi-transparent mirror140A is mechanically attached to an oscillating or rocking mechanism. Inoperation, semi-transparent mirror 140A oscillates (e.g., vertically) sothat laser beam 120 is incident on wire 110 along slightly differentpoints of impingement. Another way of obtaining full plating coverageafter laser oxide removal using only a single laser can be provided byusing additional partially transparent mirrors in conjunction withreflecting mirrors to direct the beam onto different portions of thewire.

It will be understood that vertically oscillating semi-transparentmirror 140A produces only a vertical displacement of laser beam 120,since any parallel faced transparent plate causes light to exit in thesame direction at the same angle with respect to the normal to themirror surface at which it enters the transparent plate. However, thevarying vertical displacement due to the mirror's oscillation will causea shift in the beam that allows it to impinge on different parts of thetarget (wire 110) in plating solution (not shown).

FIG. 2 shows another exemplary optical arrangement 140′ for directinglaser beam 120 onto the circumference of wire 110, located in anelectrolyte plating solution (not shown). In optical arrangement 140′,semi-transparent mirror 140A is held stationary. Additional opticalelements (e.g., lenses 140C) are interposed in the path of laser beam120 to wire 110. These optical elements 140C can be coupled to suitableoscillating or rocking mechanisms. In operation, the oscillating lensshown in FIG. 2 causes a directional and vertical shift of laser beam120 thereby permitting different parts of the target (wire 110) to beirradiated. Alternatively or additionally, optical elements 140C caninclude beam-broadening or defocusing elements, so that laser beam 120is effectively incident on the entire circumference of wire 110. Withreference to FIGS. 1 and 2, optical arrangement 140 can optionallyexploit one or more optical fibers (light pipes) to transmit laser beam120 onto the surface of wire 110. Suitable optical elements (e.g., afocusing lens) can be disposed near the optical fiber end to directlaser beam 120 onto the substrate surface.

FIG. 3 shows a system 300 for electroplating the inner surface of analuminum tube (e.g., tube 310), which is disposed in an electrolyticcell 340, which contains, for example, a copper electrolyte. Suitablemechanical rotational and translational mechanisms are connected to tube310 so that it can be rotated and translated in electrolytic cell 340.Electroplating action can be obtained by applying a suitable electropotential across, for example, a counter electrode within tube 310 and asliding contact attached to the outer surface of tube 310.

Laser beam 120 (generated by a CW or pulsed laser 130) is directed to beincident on a spot 360 on the inner surface of tube 110 by an exemplaryoptical arrangement, which includes an optical fiber 320 and otheroptical elements (e.g., lens 340) disposed within the interior of tube310. Suitable mechanical supports (e.g., optical fiber supports 330) areplaced at or near the end of optical fiber 320 within tube 310. Tube 310is mechanically translated and rotated so that spot 360 can be moved(relatively) across all the portions of the inner surface of tube 310designated for plating.

In the context of plating aluminum (and other hard-to-plate materials),FIGS. 4 and 5 show optical arrangements for moving the laser beam intwo-dimensions, leading to 2-dimensional plating. FIG. 4 shows areel-to-reel plating machine 400 with a set of optical elements 440,including two computer-controlled scanning mirrors 440A, which scan thelaser beam 420 across stock 460 in x and y directions, respectively. Thespeed at which stock 460 is fed through machine 400 can be setindependently of the scanning rate of laser beam 420.

Two-dimensional plating can also be achieved in machine 400 bycontrolling the speed of the stock to give y-direction plating withx-direction plating provided by only one scanning mirror 440A.

The arrangement of mirrors 440A for scanning the laser beam intwo-directions can also be used for plating a stationary piece of thickstock 560 submerged in the electrolyte. However, scanning mirrors 440Atypically can be able to scan only relatively small areas without thebeam spot turning elliptical because of a severe slant angle at largescanning distances. The elliptical distortion of the beam spot decreasesthe incident power/area. Therefore, for plating large areas of stock560, some motion of the stock itself can be required (FIG. 5) to avoidloss of beam spot shape. Alternatively, the loss of beam spot shape canbe overcome or avoided by having a very long path length between thefinal mirror 440A and the work piece (stock 560). In certainembodiments, the counter electrode is located in front of the substratesurface to plated, instead of as shown in FIG. 5.

FIGS. 1-5 show applied voltage polarities corresponding to platingprocesses only for purposes of illustration, and are not limiting. Itwill be understood that the systems and methods shown in the figures canbe used to etch aluminum or other stock by reversing the polarity ofvoltages applied to the two electrodes. For both plating and etching,the light irradiation serves to remove interfering surface oxide layersin situ.

The systems and methods can be advantageously used to deposit/platesolder materials onto otherwise hard-to-solder materials (e.g., Al). Thesolder materials (including, for example, lead-free solders) can bedeposited directly on the substrate (e.g., aluminum) without the use ofintermediate plating materials (e.g., copper).

FIG. 6 shows an exemplary process of soldering a copper wire 630 to analuminum substrate 610. First, substrate 610 is copper-plated in acontact region 620 using the in situ oxide removal systems and methodsdescribed above. Copper-plated contact region 620 is then soldered towire 630 using solder material 650 using conventional soldering methods.

FIG. 7 shows an exemplary process of tandem soldering two aluminumsubstrates (e.g., 700A and 700B) using the laser-assisted in situ oxideremoval systems and methods described above. First, contact lines 720Aand 720B are copper plated onto substrates 700A and 700B, respectively.Copper-plated lines 720A and 720B can then be coated or “tinned” withsolder material. Substrates 700A and 700B are then placed in contact sothat tinned copper-plated lines 720A and 720B are facing one another. Asolder joint 750 between the two substrates can be obtained by heatingthe pair of substrates in contact.

FIG. 7 shows tandem soldering is which both plated regions are facingthe same direction (upward as shown here). The solder joint is then madeso that the solder overlaps each of the two plated stripes on the twoseparate aluminum parts.

FIG. 8 shows another form of plating that can occur after in situ laseroxide removal. Here, no plating/etching electrodes are active during theoxide removal. Instead, exchange or immersion plating occurs only inthose regions in which the oxide has been removed by the laser lightpreferably, but not exclusively, in conjunction with scanning mirrors topattern the sample in the desired fashion. The advantage of this schemeis that all oxide free regions are plated to equal thicknesses sinceimmersion plating stops after a few nm have been plated by theimmersion/exchange mechanism. Following the completion of patterning andthe accompanying immersion plating, the plating supply is activated sothat plate-up of the thin immersion plated regions occurs, all regionsplated for the same length of time so that the all plated regions againhave equal plated thicknesses. If different thicknesses are desired fordifferent parts of the pattern, this can be achieved plating-up of thoseregions after immersion plating before the remaining part of the samplehas been exposed to the laser.

The disclosed subject matter also provides systems and methods for metalplating and etching of substrates that are covered by interferingsurface films. The plating and etching methods involve in situ removalof the interfering surface films or surface preparation in such a waythat plating/etching becomes possible. The in situ removal of theinterfering surface films can be obtained by in situ application ofheat, laser light, or mechanical abrasion, or by similar ex situ methodsincluding, for example, placing the substrate in a reducing gasatmosphere. Accordingly, various plating/etching cell arrangements areprovided for in situ application of resistive heating, laser light,mechanical abrasion, or reducing gas to the subject substrate just priorto or even as the subject substrate is undergoing etching or platingprocesses.

The disclosed subject matter provides convenient manufacture ofmetal-plated articles that are made from structurally desirablesubstrate materials, which are readily oxidizable (e.g., aluminum, andrefractory metals). For these metal-plated articles, the metal platingis deposited on or bonded directly to the underlying substrate materialobviating the need for intermediate substrate modification or seedlayers. The disclosed subject matter, for example, enables manufactureof metal-plated aluminum articles in which the metal coating (e.g.,nickel) is deposited directly on the aluminum substrate without anyintervening zinc or gold seed layers.

Many materials, particularly metals, develop an oxide coating or canhave some other form of a thin surface layer, which can act as aprotective coating. For those cases, it is necessary to remove the oxideor coating in some manner prior to subjecting the material to plating oretching. The removal of such surface layers is necessary forelectroplating, electroless plating, immersion plating, electro etchingand chemical etching of the material. The various plating/etchingsystems or arrangements described herein are designed to remove theprotective coatings either while or just before the materials aresubmerged in the electrolyte, which is used for carrying out the desiredplating/etching processes. These plating/etching systems or arrangementsallow removal of interfering coatings or surface films on a substrate(e.g., where the coating or surface film is a naturally grown oxide)without requiring any subsequent exposure, or at least any significantsubsequent exposure, of the substrate to air prior to placing it in aplating/etching cell. Some of the plating/etching systems are designedso that suitable preprocessing or coating removal procedures are carriedout in close proximity to the plating/etching bath, either in air or ina controlled atmosphere enclosure. Further, the plating/cell systems aredesigned to reduce and simplify the number of processing steps common inconventional metal plating/etching processes that are performed inseparate baths, tanks or ovens, and in particular to avoid thecumbersome high temperature processing steps.

Metallization/etching processing can take place in situ or immediatelyafter oxide removal so that there is no significant exposure of thesubstrate to air between the oxide removal and the plating/etchingprocessing. The disclosed processes avoids conventional expensive andsomewhat cumbersome coating removal procedures such as are presentlyrequired in plating onto, for example, an aluminum substrate.

Conventional procedures for metal plating aluminum substrates involve anumber of procedures to overcome the deleterious effects of aluminumoxide coatings that form on exposed aluminum surfaces. These procedurescan include zincating followed by gold plating before the metal ofchoice can be plated onto the aluminum substrate. By application of thedisclosed subject matter, interfering aluminum oxide materials can bereadily removed in situ by any of the several techniques describedherein, which avoid exposing the substrate material to air (or oxygen)or limit such exposure to less than a few seconds. Short exposures toair of about 1 to 10 seconds have been shown to be benign with respectto plating and etching quality. Thus, plating and etching can beinitiated immediately or within 1-10 seconds after the interferingcoating materials on the aluminum substrate are removed. This in situprocessing also can be similarly advantageous for metal plating oretching of refractory metal substrates such as tungsten, tantalum,titanium, molybdenum and rhenium.

An exemplary plating/cell arrangement or system, which is designed forin situ processing of difficult substrates (i.e., substrates whose outersurfaces are coated by an interfering film that makes direct plating oretching difficult or impossible), can include a fluid-holding tank whichcan hold a fluid electrolyte (e.g., copper sulfate, nickel sulfate orother chemical solutions), an electroless plating solution (e.g.,electroless gold) or a chemical etchant (e.g., hydrogen fluoride, sodiumhydroxide or the like). The tank can be suitably sized so that thesubject substrate (which is preferably electrically conductive) can befully submerged or partially submerged in the fluid. This exemplaryplating/cell arrangement or system can be modified to include anenclosure in close proximity or attached to the fluid-holding tank. Thisenclosure can be used for substrate preprocessing including coatingremoval prior to submerging the substrate in the fluid tank.

In one embodiment of a plating/etching cell arrangement, heat is appliedto the substrate while submerged in the plating/etching solution toremove the offending film or coating from the surfaces of the substrate.The heat can be applied as resistive heat, which is locally generated bypassing a high current through the substrate. The high current flow canbe intermittent. A first voltage/current source, whose leads areconnected to opposite ends of the substrate, is provided for thispurpose. The voltage/current source can be any suitable pulser or pulsedvoltage source that can produce a high current. Suitable pulsers producepulses that are that are greater than approximately 100 ps wide. Theresistive or Joule heating due to the passage of current within thesubstrate serve to heat the substrate, whereby this heat can lead todissolution or disintegration of the offending coating. The offendingcoating can be removed, for example, by ablation, melting, or crackingdue to differential thermal expansion. Once the coating has been removedand the pulser is no longer operating, the substrate can remain free ofcoating in the plating or etching fluid for at least about 0.1 second,but often for a much longer time on the order of minutes.

In a variation of the disclosed processes, coating removal procedures,which can be similar to the heating procedures, mechanical or othercoating removal procedures described above, can be performed beforesubmerging the substrate in the fluid tank. For such processes, theplating/etching cell system or arrangement can be provided with aseparate enclosure in close proximity or attached to the fluid tank. Theseparate enclosure can have a controlled atmosphere, which can bebeneficial to the coating removal process. For example, a reducing gas(e.g., HF gas) atmosphere can be used to remove an offending substratecoating (e.g., an oxide coating) by chemical reduction of the coating.Further, for example, an inert gas atmosphere can be used to hinderoxide regrowth during heat or mechanical coating removal procedures. Insome instances when mechanical removal of the coating can besuccessfully achieved in an air ambient, the provision of a separatecoating removal enclosure in the plating/etching cell arrangement can beunnecessary.

In any of the plating/etching cell systems or arrangements includingarrangements in which resistive Joule heating is utilized for removing acoating while the substrate is submerged in the fluid tank, acoating-free substrate can act as a working electrode while submerged inthe fluid. A suitably positioned counter electrode can be submerged inthe tank fluid for conducting electrolytic metal plating or etching. Asecond voltage/current source can be connected between the counterelectrode and the substrate to provide current for electrolytic action.In the case where the fluid is an electrolyte, the secondvoltage/current source can be activated at suitable times to causeelectrolytic plating or etching of the substrate when the substratesurface is free of the offending coating. Thus steady (continuous wave)or pulse plating and etching can be accomplished.

In a typical electroplating/electroetching process using the disclosedsubject matter in which both the coating removal process and theplating/etching process occur within the plating bath, the second sourceof voltage can be applied immediately after the current pulse applied bythe first voltage source (used for resistive Joule heating) isterminated. Alternatively, the second voltage/current source can beactivated even before or during the application of the current pulse toremove the substrate coating. In instances where the fluid in the tankis an electrolyte, it also can be possible to obtain exchange plating(e.g., immersion plating) without the use of the second voltage sourcefor certain electrolyte and substrate combinations. If the electrolytefluid contains a more noble metal than the substrate material then, oncethe offending coating is removed from the substrate surface, the morenoble metal atom will plate or deposit on the surface by replacing anexposed substrate surface atom.

The plating/etching cell arrangement also can be used for an electrolessplating (using a fluid which is an electroless plating solution). Insuch application, a catalyst in the electroless solution leads toplating without any applied voltage to the substrate electrode.Accordingly, it is not necessary to use the counter electrode and secondvoltage source to produce plating. Similarly, when a chemical etchant isused as the tank fluid, etching of the substrate can readily occurwithout the use of the counter electrode or second voltage source oncethe surface coating is removed by heat or mechanical treatment.

In yet another version of the in situ plating/etching cell arrangement,the first voltage/current source, which is used to heat the substratefor in situ removal of the offending coating layers, can be replaced asa heat energy source by any suitable energy beam that can penetrate thefluid or the gas in the enclosure of the alternate embodiment to reachthe substrate surface. The energy beam (e.g., a light beam) can begenerated by a laser. The laser beam can be directed onto the substratesurface through an optical fiber or an optical wave-guide (e.g., a lightpipe). Alternatively, the laser beam can, in certain instances, bedirected onto the substrate through the electrolyte without the use of alight pipe or optical fiber.

Similar localized surface heating can occur with the use of either thevoltage source or the laser beam as the heat or photoablative energysource for removing the substrate coating while the substrate issubmerged or is in the preprocessing enclosure. The plating/etching cellarrangement can be configured with a suitable fluid stirring mechanismto mitigate any local boiling of the fluid or bubble formation incontact with the substrate. For example, a circulating flow system usingpump can be used as a fluid stirring mechanism. The circulating flowsystem can be pressurized by way of the pump and use gravity flow toform a complete closed system for agitating the fluid. Alternatively oradditionally, a mechanical magnetic stirrer can be placed within thefluid containing tank to maintain fluid agitation as is well known tothose skilled in the art.

In an alternate version of the plating/etching cell arrangement, amovable scraping or abrasion tool is provided to remove the offendingcoating by applying mechanical force to the substrate. The scraping orabrasion tool can be scanned across the substrate to remove thesubstrate's coating. Mechanical removal of the offending coating can bein addition or as an alternate to, other removal techniques describedherein, such as heat-based removal (i.e., using the first voltage sourceor the energy source to remove the coating of the substrate in situ).

An exemplary scraping or abrasion tool can be a mechanical scribe with asharpened end, which is placed in intimate contact with the substratesurface. In operation, the scribe mechanically penetrates the coating.The mechanical scribe can be driven by a motorized moveable arm, whichis preferably digital data processing device controlled. As the scribetraverses the areal dimensions of the substrate, the coating is removedfrom the substrate surface. Removal of the coating allows plating andetching of the substrate surface to occur immediately thereafter, whilethe scribe and the substrate are submerged in the plating/etchingsolution or, alternatively, while the scribe and substrate arepositioned in the preprocessing enclosure.

In some versions of the plating/etching cell arrangement in which theoffending coating is removed within the plating/etching bath, themechanical scribe can be used in conjunction with the first voltagesource to remove a coating by application of both resistive (Joule)heating and mechanical force to the substrate surface. In such versions,the mechanical scribe can be made from conducting material, which allowslocalized current to flow from the scribe to the substrate. In apreferred embodiment of such a version of the plating/etching cellarrangement, the mechanical scribe is disposed to make contact with theback of the substrate (which can be sheet or flat stock). In thisconfiguration, current that is supplied from the first voltage sourceflows through the substrate and heats the front of the substrate toremove the coating on the front surface of the substrate to be plated oretched (i.e. the surface facing the counter electrode).

The in situ plating/etching cell arrangements can be configured tooperate with reel-to-reel material handling systems that are commonlyused in industrial processing of long lengths of wire or sheet flatstock. In these reel-to reel material handling systems, the unprocessedsubstrates (i.e., long length of wire or sheet flat stock) are wound ona donor reel and fed into the processing fluid (tank fluid) by a seriesof support wheels. Processed substrates are similarly picked up by aseries of wheels and wound on a mechanically driven take-up reel. Thedisclosed in situ plating/etching cell arrangements can be provided withsuitable scrapers for mechanically removing the offending coating on thesubstrate surface in situ in the processing fluid or in a smallpreprocessing enclosure in close proximity to the fluid. For example,the substrates can be driven or pulled through a die that removes thecoating by way of a sharpened inner peripheral die surface (i.e. a knifeedge). The substrate feed rate can be adjusted by suitably setting thespeed of the reels. The substrate feed rate for the plating/etchingprocesses can be selected so that the wire or flat stock substratesremain submerged in the plating/etching tank fluid for at least 0.1 s,as the substrates are pulled through the die using the mechanicallydriven take-up reel. The shape of the die (e.g., circular orrectangular) can be designed in consideration of the shape of thesubstrate material (e.g., wire or flat stock).

In some versions of the plating/etching cell arrangements, the diestructures can be used in conjunction with the first source of voltageto apply heat to wire or flat stock substrates as they pass through thedie. For example, opposite ends of a die can be used to pass current andto cause heating as the wire or flat stock passes through the die. Thisheating mechanism can be used as an alternate or an additional mechanismfor removal of surface coatings. In another embodiment, heat can begenerated directly in the wire or flat stock by contacting a voltagesource by means of sliding contacts to the wire/flat stock directly,thereby using the resistance of the wire/flat stock in conjunction withcurrent flow to generate the necessary heat to remove the coating.

After removal of surface coatings using the die, a second voltage can beapplied to the wire or flat stock substrate across from a counterelectrode to cause electroplating or electroetching.

Examples of plating/etching processes and cell arrangements are furtherdescribed herein with reference to FIGS. 9 a, 9 b, 10-14, 16 a-16 d, 9,and 19-20. Any one, or more of these arrangements can be combined withthe optical arrangements disclosed herein (e.g. disclosed in FIGS. 1-5).

FIG. 9 a shows an exemplary plating/etching cell arrangement 100 for insitu removal of interfering surface coating during plating/etching ofsubstrates 103 in a plating tank or vessel 101. Tank 101 contains anelectrolyte 102, which can be either plating or etching bath. Thesubstrate material to be plated or etched (i.e. substrate 103) issubmerged in electrolyte 102.

In general, a plating bath can be an electroless, electroplating orimmersion plating or other chemical solution. For etching, the bath canbe a chemical etchant such as sodium hydroxide or any other etchantknown to those skilled in the art. For electroetching, the etchant can,for example, be a copper sulfate solution. Plating/etching cellarrangement 100 can be provided with an optional counter electrode 104,which is used only for those applications that utilize eitherelectroplating or electroetching. For immersion plating and electrolessplating as well as for chemical etching, use of this electrode isunnecessary. A galvanostat 105 can provide the required electrolyticcurrent for electroplating and electroetching. A simple voltage/currentsupply can also be used in its place. It will be understood that forelectroless and immersion plating as well as for chemical etching,galvanostat 105 and counter electrode 104 need not be used.

Initially in the plating/etching process, a high current pulse is passedthrough substrate 103 using a first source of current/voltage (i.e.pulse generator 109). Pulse generator 109, which can be connected acrossopposite ends of substrate 103 by wires 110 and 111, supplies currentpulses through substrate 103. Pulse generator 109 can be any suitablecurrent source capable of generating current pulses, which, for example,have spans ranging from tens of pico seconds to continuous wave (CW).The current pulses can be designed to heat substrate 103 or its surfaceswhile it is immersed in 102. Substrates 103 or its surfaces can beheated sufficiently by the current pulses so that the interferingsurface coating is removed. For electroplating and electroetching, asecond source of voltage/current is provided by source 113. Source 113can be utilized prior to the heating current pulse applied by pulsegenerator 109, concurrently, or at any time thereafter.

A fluid circulation system can be set up to agitate the fluid containedin tank 101 to avoid or inhibit boiling or bubbling in the fluid at thesurfaces of substrate 103, which can be induced by localized heatingcaused by passage of the current pulse. The circulation system caninclude a pump 106 with an input 107 to tank 101, and a drain 108.

FIG. 9 b shows a more detailed view an exemplary fixture assemblydesigned to hold substrate 103 in tank 101. The fixture assemblyincludes a pair of metallic posts 1001, each of which is made from twoseparate metal sections 1003 and 1004. Metal sections 1003 and 1004 canbe rectangular in shape and can be held together by mechanically (e.g.,by bolts 1002 with 1003 clamped between sections 1003 and 1004).Metallic posts 1001 can be fastened to a base plate (not shown) thatallows posts 1001 to rest on the bottom of tank 101. Pulser 109 can beelectrically connected to substrate 103 by a pair of connecting wires110 and 111 running along substrate support posts 1001. A similarfixture assembly can be used to hold counter electrode 104 when such anelectrode is used. The dimensions of metal sections 1003 and 1004 can beselected so that their widths 1005 are small compared to the distancebetween them. Posts 1001 can have any suitable thickness (e.g., of theorder of 1-5 mm). Posts 1001 can be made of material, which preferablyhas high electrical conductivity (e.g., copper posts for copperplating/etching). An insulating sleeve can enclose portions of post 1001below substrate 103 to avoid plating or etching of post 1001 itself. Itwill be understood that the fixture assembly shown in FIG. 1 b isexemplary, and that one skilled in the art can readily designalternative fixture assemblies.

FIG. 10 shows yet another exemplary plating/etching cell arrangement200, in which a laser 207 is exploited to irradiate substrate 203 to beetched or plated. In plating/etching cell arrangement 200, substrate 203can be at least partially submerged in an electrolyte or otherplating/etching solution 202 contained within a tank 201. A counterelectrode 204 for electroplating and electroetching is also submerged insolution 202 in tank 201. A galvanostat or other voltage/current supply205 can be connected via wires 209 and 210 to impose an electricpotential difference between counter electrode 204 and substrate 203.Counter electrode 204 and galvanostat 205 are not used whenplating/etching cell arrangement 200 is used for electroless, immersionplating or chemical etching of substrate 203.

Laser 207, which is disposed external to tank 201, can be configured sothat its output light is directed into a light pipe or light fiber 206extending into tank 201. Light fiber 206 can be suitably oriented sothat the laser light output is incident on substrate 203. Laser 207 canbe suitably pulsed to generate light pulses with pulse widths (e.g.,ranging from a few femtoseconds, or ps, to hundreds of microseconds).For some applications longer pulses extending to cw operation can beused. A laser voltage control unit 208 can be used to set the pulsewidth and pulse intensity of laser 207. Laser 207 can have a laserwavelength in the range of about 0.1-10 micrometers. Laser 207 can, forexample, be a near infrared or infrared laser emitting radiation atwavelengths that are suitable for absorption in and heating of thesubstrates. The intensity and duration of the laser light incident onsubstrate 203 can be theoretically or empirically designed to removecoatings from the surface of substrate 203 by heating. Thecoatings/substrate can be sufficiently heated to bring about coatingremoval by ablation, differential expansion of the coating and thesubstrate leading to cracking of the coating, melting or any by othermechanism. Alternatively, laser 207 can be an ultraviolet laser emittingradiation at wavelengths that are suitable for photoablativedecomposition and removal of the inhibiting layer without substantialheating of the substrates.

With reference to FIG. 10, Substrate 203 can be mounted on a moveablearm 211 assembly, which can be operated by a digital data processingdevice (not shown) to move substrate 203, for example, in vertical andhorizontal directions. By coordinating the pulsing of laser 207 with themovement of substrate 203, patterned coating-removal, plating or etchingof substrate 203 can be obtained. The degree of etching or plating ofsubstrate 203 can be controlled by varying the intensity of laser 207,for example, by using voltage control unit 208 after the coating hasbeen removed. Additional contrast in the pattern on substrate 203 can beachieved by making counter electrode 204 comparable in diameter to thatof light fiber 206 to limit the region of plating as a function ofposition of substrate 203. Suitable contrast in theelectroplating/etching patterns on substrate 203 also can be obtained bycontrolling the voltage between counter electrode 204 and substrate 203as arm 211 is set into motion. For this purpose, galvanostat 205 can beprogrammed using any suitable digital data processing device ormicroprocessor (not shown). Laser light from laser 207 can also be aimeddirectly at the substrate 203 without the use of fiber 206.

FIG. 11 shows another exemplary plating/etching cell arrangement 300, inwhich a sharp probe or pointed scribe 306 is used to remove the surfacecoatings on substrate 303, while the latter is submerged in theplating/etching solution 302 in tank 301. Solution 302 can be anelectrolyte or a process liquid used to cause plating or etching forcases where no external voltage need be supplied to a counter electrode.In tank 301, electrolyte (or process liquid) 302 at least partiallycovers substrate 303. Sharp probe or pointed scribe 306 can be mountedon moveable arm 307, which can be set in motion by a translation motorand digital data processing device (not shown). Sharp probe or pointedscribe 306 can be spring loaded or biased so that it is in mechanicalcontact with substrate 303. The contact pressures can be suitably set sothat movement of scribe 306 across the surface of substrate 303 by arm307 results in removal of coating or oxide layers on substrate 303.

In plating/etching cell arrangement 300, an optional counter electrode304 is attached to a galvanostat or voltage/current supply 305. Forelectroplating or electroetching of substrate 303, a voltage can beapplied between counter electrode 304 and substrate 303 before, during,or after moving scribe 306 along the surface of the substrate 303. Itwill be understood that for electroless, immersion plating and chemicaletching processes, galvanostat 305 and counter electrode 304 are notneeded or activated.

FIG. 12 shows another plating/etching cell arrangement 400, in which asharp probe or pointed scribe 410 is used to deliver an electricalcurrent generated by a high current pulser 405 for passage throughsubstrate 403 (and its surface coatings), while the latter is submergedin the plating/etching solution 402 in tank 401. The electrical currentpulses can be designed to dissipate and resistively heat the surfacecoatings on substrate 403 to induce their removal.

In plating/etching cell arrangement 400, pointed scribe 410 is springloaded and can rest on either the front or back surface of substrate403. In the example shown, pointed scribe 410 rests on the back surfaceof substrate 403. Further, pointed scribe 410 can be mounted on moveablearm 406 so that it can be moved along the surface of substrate 403 in acontrolled manner (using, for example, a controller and digital dataprocessing device (not shown)). An optional insulation material 407 cancover portions of moveable arm 406 to isolate those portionselectrically or chemically. As arm 406 together with spring loadedscribe 410 is moved along the back of substrate 403, a pulser 405 candeliver a pulse of current or a cw current (depending on the settings ofpulser 405) through scribe 410. For this purpose, current pulser 405 canbe connected to pointed scribe 410 and to substrate 403, by connectingwires 411 and 412, respectively. The current transmission through thepoint of contact of scribe 410 on the back of substrate 403 results inlocalized heating to remove localized regions of coating on both thefront and back surface of 403.

Counter electrode 404, which faces the front surface of substrate 403,can be operated in conjunction with galvanostat or voltage source 408 atany time during the coating removal process to cause plating or etchingof front surface regions of substrate 403. These front surface regionscorrespond to regions of the back of substrate 403 where scribe 410 hasdelivered current. In certain embodiments, the counter electrode canalso be placed behind electrode 410 if the sample is thick and only theback surface is desired to be plated or etched. It will be understoodthat for electroless, immersion plating and chemical etching,galvanostat 408 and counter electrode 404 are not needed or activated.

The plating/etching cell arrangements can be adapted for use with knownindustrial material handling systems (e.g., reel-to-reel systems forwire and flat stock substrates). FIG. 13 shows a plating/etching cellarrangement 500, which is configured for processing wire substrates 513.Plating/etching cell arrangement 500 includes a tank 501 for holdingelectrolyte or other plating/etching chemical solutions 502. A die witha sharp inner edge 503 rests on a die support post 505 within tank 501.Coated or partially coated (e.g., oxidized) wire substrate 513, which isused as raw material, is wound on a donor reel 506. From reel 506, wire513 is guided by a set of guide wheels 511 into tank 501 containingprocessing fluids or solutions (e.g., electrolyte 502). Wire 513 ispulled or drawn through a die 503 having knife-edges for stripping orscraping undesirable coating material from the wire substrate surface.An exemplary annular design of die 503 is shown in the inset in FIG. 13.Exemplary die 503 can have split annular rings 509, which are clamped(e.g., with one or more screws 510) around wire substrate 513. Wiresubstrate 513, which is passed through die 503, also can be passedthrough a similar hole or opening in counter electrode 504 (forapplications involving electroplating or electroetching) to facilitatecontinuous movement of wire substrate 513 through tank 501. Additionalguide wheels 511 can direct processed wire substrates 513 out of tank501 onto a take-up reel 507. Die 503 can have a sharp innercircumferential portion (e.g. a knife edge 514) designed to scrape thesurface of passing wire substrate 513 to remove any surface coatings sothat unhindered plating or etching of the wire substrate material cantake place. The rate at which wire substrate 513 is processed throughplating/etching cell arrangement 500 can depend in part on the rotationspeeds of reels 506 and 507. The rotation speeds of reels 506 and 507can be controlled, for example, by a digital data processingdevice-controlled drive motor (not shown) or by any other suitableconventional mechanical mechanisms. For electroplating andelectroetching processes conducted in plating/etching cell arrangement500, a galvanostat 508 (or any other suitable current/voltage source)can be connected to the die 513 and a counter electrode 504 usingconnecting wires 514 and 512, respectively.

FIG. 14 shows a plating/etching cell arrangement 600, which isconfigured for processing flat stock substrate 615. Plating/etching cellarrangement 600 includes a tank 601 for holding electrolyte or otherplating/etching fluid 602. A die with a sharp inner edge 603 rests on adie support post 605 within tank 601. Coated or partially coated(oxidized) flat stock substrate 615 can be fed from a donor reel 605over a set of guide rollers 606 into tank 601. In tank 601, flat stocksubstrate 615 is pulled or driven through a die 608 with a rectangularopening. Die 608 can be mounted on support 621 disposed on the bottom oftank 601. Die 608 can have knife-edges or blades disposed in therectangular opening for stripping or scraping undesirable coatingmaterial from the flat stock substrate surface. For electrolytic platingor etching processes, the cell arrangement 600 can be provided with aslotted counter electrode 604 to facilitate passage of processed flatstock substrate 615 through tank 601 onto take-up reel 607. Agalvanostat (voltage/current source) 603 can be connected to die 608 andcounter electrode 604 by suitable wires 611 and 612, respectively.

An exemplary design of die 606 is shown in the inset in FIG. 6. Die 606can be assembled from two split sections 609 and 610 that are heldtogether by bolts 611. The dimensions of the rectangular opening in die606 can be selected so that scraping blade 620 acts against the surfaceof flat stock substrate 615 passing through the opening and mechanicallyremoves coating or oxide materials, which can be present on the surface.

In certain embodiments, die 503 and die 608 in plating/etching cellarrangements 500 (FIG. 13) and 600 (FIG. 14), respectively, canadditionally or alternatively be employed as heaters to provide energypulses for heat removal of the coating or oxides on the in-process wireor flat stock substrates. In such applications, the dies can be suitablymodified and connected to a voltage/current source to deliver currentpulses to the substrate, for example, in a manner similar to the onepreviously described with reference to plating/etching cell arrangement100 (FIG. 9 a).

FIG. 15 shows in partial cross-section the layered structure of ametal-plated article 700, which can be fabricated using, for example,plating/arrangement 600. Metal-plated article 700 includes a flat stocksubstrate core 710 made of readily oxidizing material (e.g., aluminum ora refractory metal). A metal plated layer 720 is disposed directly onthe surfaces of core 710, any inhibiting or interfering surface coatinghaving been removed. Metal plated layer 720 can be any desired platingmaterial (e.g. nickel, silver, gold, copper, cadmium, etc.).

It will be understood that metal plated layer 720 can be formed byexchange plating from the chemical solution, which can take place afterin-situ removal of inhibiting or interfering surface coatings byapplication of heat pulses or abrading action (FIGS. 9-15). Additionalelectroplating using a voltage supply or potentiostat can not berequired when the usually very thin coatings obtained by exchangeplating are sufficient, for example, by design of metal-plated article700.

FIGS. 16 a-16 d and 17 show plating/etching cell arrangements 800 and900, in which coating removal procedures are performed before thesubstrates are immersed in plating/etching baths 801 and 901,respectively. These arrangements can include controlled atmosphereenclosures 803 or 903 in which the coating removal procedures and/orother substrate preprocessing procedures can be performed. Theenclosures can be in close physical proximity to the plating/etchingbaths (e.g., enclosure 803 FIGS. 16 a-16 c) or mounted directly on theplating/etching baths (enclosure 904, FIG. 17). FIG. 16 d shows aplating/etching cell arrangement 800 in which a mechanical coatingremoval can be performed in ambient air just prior to immersion of thesubstrate in the plating/etching bath 800.

With reference to FIG. 16 a, plating/cell arrangement 800, whichincludes a plating/etching bath tank 801 holding an electrolyte 8001 anda controlled atmosphere enclosure 803, is configured for operation witha reel-to-reel substrate material handling system. The material handlingsystem can include supply and pick-up reels 805 and 809, respectively.Raw wire or flat stock 806 unwound from supply reel 805 is passedthrough enclosure 803 before being processed in plating/etching bathtank 801 and being rewound on pick-up reel 809. The walls of enclosure803 can be provided with slots or openings of suitable dimensions (notshown) to accommodate the passage of raw wire or flat stock 806 throughenclosure 803. A mechanical abrasion die 804 can be located in enclosure803 to provide the necessary mechanical contact with wire or flat stock806 to remove the unwanted coating from the surfaces of stock 806, forexample, by friction. The atmosphere in enclosure 803 can be controlledduring the coating removal processes. Inert or non-oxidizing atmospheresmade of gases such as nitrogen, helium, or argon can be desirable toinhibit or hinder reoxidation of cleaned substrate surfaces. Thesuitable specific gas or gases can be supplied from a gas source 802connected to enclosure 803. In operation, undesired coatings arestripped from the surface of wire or flat feed stock 806 in enclosure803 by mechanical die 804 so that stock 806, which passes intoplating/etching bath 801, has a clean surface.

Mechanical abrasion die 804 also can serve as an electrical contact towire or flat stock 806. A voltage source or potentiostat 807 connectedto abrasion die 804 can be used to apply an electrical voltage to wireor flat stock 806 across from counter electrode 808 to obtainelectroplating or etching action as coating-free wire or flat stock 806passes through electrolyte 8001. Processed wire or flat stock 806 isdrawn out of electrolyte 8001 and wound on pick-up reel 809.

FIG. 16 b shows a variation of the plating/etching cell arrangements 800in which mechanical abrasion die 804 is replaced by a heatingarrangement 8041. Heating arrangement 8041 is configured to make a pairof electrical contacts 8042 with wire or flat stock 806 as the stockpasses through enclosure 803. A voltage applied across the pair ofelectrical contacts 8042 by heating arrangement 8041 causes anelectrical current to flow through the intervening section of stock 806.The magnitude of the electrical current can be suitably selected tocause sufficient resistive or Joule heating to remove the unwantedcoating/film from the surfaces of stock 806. The heating process can beconducted in an inert gas atmosphere, which is supplied from gas tank802, to minimize surface oxidation or reoxidation.

FIG. 16 c shows another variation of plating/etching cell arrangement800 in which laser heating is employed instead of mechanical abrasion orJoule heating to remove unwanted coatings from the surface of wire orflat stock 806 passing through enclosure 803. A laser 8042 can bedeployed to direct light onto wire or flat stock 806 passing throughenclosure 803. Laser 8042 can be selected to have a light wavelengthsuitable for absorption in and consequent heating of the stock materialor absorption in the inhibiting film itself giving rise to photoablationof the inhibiting film (e.g. using a post laser or pecosecond postlaser). In operation, laser 8042 can be operated at a power sufficientto heat wire or flat stock 806 so that unwanted surface coatings areremoved as wire or flat stock 806 moves through enclosure 803. Voltagesource or potentiostat 807 can be configured to make a slidingelectrical contact 8044 with wire or flat stock 806 as the stock passesthrough enclosure 803. Voltage source or potentiostat 807 can be used toapply an electrical voltage to wire or flat stock 806 across fromsliding contact 8044 and counter electrode 808 to obtain electro platingor etching action as coating-free wire or flat stock 806 passes throughelectrolyte 8001.

In another embodiment of plating/etching cell arrangement 800, removalof unwanted surface coatings can be accomplished by chemical action. Insuch an embodiment, enclosure 803 can be configured to hold a reducinggas atmosphere (e.g., hydrogen) to treat the surfaces of passing wire orflat stock 806 to remove unwanted coatings.

It will be understood that in FIGS. 16 a-16 c, enclosure 803 is shown asseparated from tank 801 by an arbitrary distance, which is selected onlyfor visual clarity in illustration. In practical implementations ofplating/etching cell arrangements 800, enclosure 803 can be separatedfrom tank 801 by a distance selected in consideration of the tolerabletransit time of cleaned stock 806 through air prior to plating oretching action. In some embodiments, enclosure 803 can be attached totank 801 so that cleaned wire or flat stock 806 can exit directly intotank 801. Such implementations minimize the time cleaned wire or flatstock 806 is exposed to air before submerging in electrolyte 8001.

Conversely, for certain applications in which air exposure times are nota significant issue (e.g., the plating or etching of cleaned aluminum),enclosure 803 can be completely dispensed with. FIG. 16 d shows aplating/etching cell arrangement 800, which is configured for processingmaterials such as aluminum. In this configuration, surface coatings canbe adequately removed from aluminum wire or flat stock 806 by mechanicaldie 804 in air without the benefit of a controlled atmosphere ofenclosure 803. It will be understood that mechanical die 804 is placedin close proximity to tank 801.

FIG. 17 shows another plating/etching cell arrangement 900, which isadapted for processing substrates that are not conveniently supplied byreel-to-reel material handling systems. The substrates can be discreteindividual parts or parts having non-flat geometrical shapes.Plating/etching cell arrangement 900 is designed so that unwantedsurface coatings can be removed from substrate 906 having any arbitraryshape prior to etching and plating. Plating/etching cell arrangement 900includes a tank 901 which can hold an electrolyte 902. An enclosure 904,which has a substrate loading door 9004, is disposed directly atop tank901. Enclosure 904 is provided with ports 903 and 912 that can be usedto flow gases through the enclosure. A sliding access door 905 can beprovided between enclosure 904 and tank 901. Substrate 906 can be loadedthrough loading door 9004 and attached by fastener 908 to substrateholding rod 907, which can be adapted for controlled vertical motion toposition loaded substrate 906 in either enclosure 904 or tank 901. Rod907 is also connected to a terminal of voltage supply or potentiostat910 by way of a wire lead 909.

In preparation for plating or etching in tank 901, substrate 906 isfirst suspended in enclosure 901. A reducing gas (e.g., hydrogen) can bepassed over substrate 906 through ports 903 and 912 to chemically reduceand remove unwanted surface coatings. After removal of the unwantedsurface coatings, substrate 906 can be lowered through sliding door 905into electrolyte 902 for plating or etching action on cleaned substratesurfaces. The intimate proximity of enclosure 904 and electrolyte 902inhibits re-oxidation of substrate 906 between the coating removal andinitiation of plating or etching action. For plating or etching actionby electrolyte 902, a potential difference can be established betweensubstrate 906 and a counter electrode 911 by connecting electrode 911 tothe opposite polarity terminal of supply 910.

FIG. 18 shows an exemplary composite substrate 1000, which can be platedor etched using the disclosed systems and methods. Substrate 1000 can,for example, include a silicon, or glass base 1001 on whose surface afilm 1002 is deposited. An inhibiting film 1003 can reside on top offilm 1002. Removal of film 1003 (and/or film 1002) can be necessary forsuccessful plating or etching of composite substrate 1000. Such removalcan be effected using the systems and methods described herein.

The disclosed subject matter also provides additional techniques andarrangements for in situ removal of inhibiting or interfering surfacefilms to prepare substrates for plating and/or etching. These additionaltechniques include induction heating, microwave heating and mechanicalstamping processes. The additional techniques can be individually usedto prepare substrates for plating and/or etching. Alternatively, thetechniques can be used in any suitable combination (e.g., abrading andstamping, stamping and microwave heating, etc.) to prepare substratesfor plating and/or etching as known to a person of ordinary skill in theart.

Induction heating is a known method for providing fast, consistent heatto a metallic object. Induction heating is used in many manufacturingapplications, including, for example, bonding, annealing, metal workingand the like. In common induction heating arrangements, an ac coil(i.e., induction coil) is placed in close proximity to a work piece orsubstrate. The ac coil radiates a time-varying electromagnetic field,which induces eddy currents in a surface layer (“skin depth”) of themetal or metallic work piece/substrate. These eddy currents dissipateenergy in the skin depth causing the temperature of the workpiece/substrate to rise. The thickness of the “skin depth” of the metalor metallic work piece/substrate depends on the frequency of the accurrent driving the induction coil and on the intrinsic electricconductivity of the metal or metallic work piece/substrate. The overallwork piece/substrate heating is also a function of the thermalconductivity, geometry and the immediate environment of the workpiece/substrate.

In the disclosed subject matter related to metal plating and etching,substrates are subjected to induction heating to remove inhibitingsurface films or regrowth. The substrates can be inductively heated whenthey are either (1) submerged in a plating/etching solution bath or (2)contained within an inert atmosphere in a preparation chamber in closeproximity to the plating/etching bath.

FIG. 19 shows such a preparation chamber, which can be used to preparesubstrates for plating/etching. The substrates can be inductively heatedin an inert atmosphere to remove inhibiting oxide or other films.Immediately after the inductive heating, the substrates can be subjectedto etching or plating action. FIG. 19 shows an arrangement in which thepreparation chamber is separated from the plating/etching tank by apartition wall. Substrates that are inductively heated in thepreparation chamber can be rapidly transferred to the plating/etchingtank through a sliding door in the partition wall.

The substrates can be inductively heated using either continuous wave(cw) or pulse heating in the inert atmosphere to remove inhibiting oxideor other films. The frequency of the radiated electromagnetic fieldproduced by the induction coil at least in part determines the depth ofheating of the substrate. The higher the frequency of the radiatedelectromagnetic field the greater is the localized surface-like natureof the heating of the substrate, due to the well known electromagneticskin depth effects. In most instances, there is no need to heat the bulkof the substrate for simply removing the inhibiting surface films. Forlocalized surface heating, which is most effective for removal ofinhibiting surface films, it can be desirable to use inductionfrequencies greater than 60 kHz. A practical frequency regime is atleast 100 kHz or greater. Subjecting the substrate to GHz microwaveradiation, which is typically generated by a magnetron, can beespecially effective in removing the inhibiting film by localizing theheating to a thin surface region. A magnetron-microwave system forremoving inhibiting films is also shown in FIG. 19.

Induction heating or microwave irradiation heating for removing surfaceinhibiting films can be most effective in a preparation chamber separatefrom the plating/etching bath in order to inhibit heating ofplating/etching solution itself.

In some instances, induction heating also can be exploited to heatsubstrates that are submerged in a plating/etching solution. Suchinduction heating is likely to also heat the plating/etching solution.Circulation and/or cooling of the plating/etching solution can overcomeany undesirable or excessive heating of the plating/etching solutioncaused by induction heating.

FIG. 20 shows a preparation chamber 1201 in which microwave or inductioncoil heating is used to remove a thin oxide or inhibiting film fromtrenches in a substrate prior to plating action. The substrate can, forexample, be a semiconductor silicon substrate that has trenches built inits surface as part of common semiconductor device fabricationprocesses. FIG. 20 shows a substrate topography with only one trench forpurposes of clarity in drawing. It will be understood that the substratecan be a silicon wafer substrate, which in typical semiconductor devicefabrication processes can have thousands or several thousands of suchadjacent trenches in close proximity to each other. In currentsemiconductor device fabrication processes, it is desirable to be ableto plate copper in the trenches for making electrical conductor lines.To plate copper on silicon to make electrical conductor lines, a liner(e.g., a thin film of Ta or TaN) is first deposited in the trenches ontothe silicon trench surface itself or on an intermediary thin layer ofsilicon dioxide.

As an alternative or in addition to the induction heating and/ormagnetron heating techniques already described, ion beam heating can beused to prepare substrates for plating. The ion beam heating techniquecan be particularly suited for preparing “trenched” substrate topographyfor plating/etching. FIG. 21 shows an arrangement 1300 with a movableion gun (e.g., ion gun 1301 with lateral and rotational motion). Thearrangement can be used for an ion beam process to prepare an array oftrenches on a wafer surface for subsequent plating action. As shown inFIG. 21, a directed ion beam generated by the ion gun can be made toscan the wafer surface in swivel and/or raster pattern. Typically, thewavelength of ion beam is in the submicron range so that the beam canreach into the trenches in a manner that is not possible by typicalwavelength laser light. The energy of the ion beam determines theeffective particle wavelength. For example, for a 400 eV argon ion beam,the wavelength is on the order of 1 A. The wavelength or energy of theion beam can be adjusted by changing the number of electron volts ofacceleration voltage applied to the ion beam. The ion beam energy isadjusted so that it is sufficiently energetic to remove the inhibitinglayer without affecting the liner as shown in FIG. 21.

FIG. 22 shows the use of an induction coil (or magnetron) heatingarrangement 1400 in a reel-to-reel system for plating/etching continuoussubstrates (e.g. shim stock). In the configuration shown in FIG. 22, aninduction coil or magnetron is provided in a preparation chamber 1401.The raw substrate material from the stock reel passes through thepreparation chamber, which can contain an inert gas or a vacuum. Thepassing substrate material is inductively heated in chamber 1401 usingeither a cw or pulsed mode radiation. The substrate material then passesdirectly into the plating/etching bath after which it is rewound on atake-up reel. The system of FIG. 22 is similar to the reel-to-reelsystems described, for example, with reference to FIGS. 16 a-16 d,except for the manner in which the substrates are prepared forplating/etching. The systems of FIGS. 16 a-16 d use direct currentheating or the mechanical abrading of the raw substrate as it is unwoundfrom the reel prior to entering the plating/etching bath followed byrewinding on a take-up reel. In contrast, the system of FIG. 22 usesinduction heating of the raw substrate material prior to metalplating/etching.

Another mechanical surface film removal technique can be utilized toremove inhibiting coatings, for example, from substrates that are shapedby stamping processes. In such processes and with reference to FIG. 23,a stamping tool 1500 is driven by force against the substrate to changethe latter's mechanical form into a desired pattern or shape. Thestamping processes can be operated either at room temperature or heatedtemperatures. When sufficient force is used to drive the stamping tool,the stamping processes not only serve their primary function ofmechanically shaping the substrate, but also can result in removal ofthe inhibiting coating (e.g., a thin oxide layer).

According to the disclosed subject matter, a substrate stampingoperation is conducted in conjunction with and in close proximity to themetal/plating operations. The stamping operation is conducted just priorto moving the resultant shaped substrate into a plating or etching bath.The shaped substrates, free of inhibiting coatings after stamping, aremoved rapidly to the plating bath in a short time interval to inhibitany significant re-oxidation.

The stamping operation can be carried out in air, vacuum, or an inertgas. With suitable selection of the stamping process parameters andconditions, the stamping operation makes it possible to plate onto there-shaped metal substrates that normally cannot be plated or aredifficult to plate due to inhibiting films. New types of substratematerials can be used to substitute or replace current substratematerials for industrial applications. For example, presently copper orcopper alloys are used in the connector industry for making connectors.Conventional connectors are made by stamping copper substrates or sheetsand then plating them (e.g., with gold). With the disclosed subjectmatter, it will be possible to use aluminum or titanium metal forconnectors with plating occurring after stamping. The combination ofstamping operations with metal/plating operations according to thedisclosed subject matter is particularly suited for use by the connectorindustry in which stamping operations are usually undertaken prior toplating.

FIGS. 24 and 25 show other exemplary plating/etching cell arrangements,in which removal of the inhibiting oxide or film and subsequent platingoperations are performed in two separate tanks. The provision of twoseparate tanks permits flexibility in selecting process conditions forthe removal and plating processes independently. FIGS. 24 and 25 shows areel-to-reel system 6000 having two separate tanks 6005 and 6014 foroxide removal and plating, respectively. Tanks 6005 and 6014 can beenclosed in an optional inert atmosphere enclosure 6004. In system 6000,material 6002 is supplied from reel 6001 and processed material ispicked up by reel 6003. Material 6002 passes from supply reel 6001 byway of small tracking wheels 6015 into the bath of the first tank 6005and then into tank 6014. Tank 6005 can contain a bath (e.g., a acid suchas sulfuric acid, or a base such as sodium hydroxide) in which theinhibiting layer on material 6002 is removed by application of a shortelectrical pulse from a high voltage pulser 6006 to the supply reelmaterial 6002. As seen in FIG. 24, high voltage pulser 6006 has closelyspaced electrode contacts 6007 which make contact with material 6002.The duration of the electrical pulse, which is applied across contacts6007, can be about 10 nanoseconds to about 100 milliseconds. Theparticular voltages selected for the electrical pulse can depend on thepulse duration. Higher voltages can be required for shorter pulses.Further, a repetition rate of pulser 6006 can be determined by the speedof the reels. In order to obtain a continuous inhibiting film removal,the pulse repetition rate can be about 1-10,000 times per second.

Alternatively or additionally, the inhibiting layer residing on material6002 can be removed by means of laser heating or photoablation. FIG. 25shows an arrangement in which laser 6101 emits a laser beam 6102 whilematerial 6002 is immersed in tank 6005 before it is plated in secondtank 6014. The setup in FIG. 25 is similar to that shown in FIG. 24except that pulser 6006 supplying electric pulses to material 6002 infirst acid/base tank 6005 is replaced by a pulsed or CW laser 6101positioned external to tank 6005. Laser 6101 is positioned and operatedso that laser beam 6102 is incident on material 6002 in first tank 6005.In operation for oxide or inhibiting film removal, the laser pulses canhave a width in the range of 1 ns to 100 ms with a preferred value inthe range of about 10 femtoseconds to 10,000 microseconds. The pulserepetition rate can be in the range of about 1-100,000 pulses persecond. The laser wavelength can be in the range of about 0.1 to 10micrometers. It will be understood that in the case where laser 6101 isa CW laser, suitable electromechanical and/or optical scanningmechanisms can be provided to scan the laser beam with respect to thesurface of material 6002 undergoing plating or etching.

The acid or base used in tank 6005 is preferably the same acid or baseused in plating bath 6011, which is contained in the second tank 6014.The acid or base used in tank 6005 is free of plating metal ions.Cross-contamination or compositional change of plating bath 6011 insecond tank 6014 can result if fluids from the first bath adhere tomaterial 6002 upon exiting tank 6005 and are transferred to tank 6014.To avoid such compositional change, material 6002 exiting tank 6005 canbe wiped clean using, for example, wiper blades 6013. Wiped liquids canbe collected in and drained from drag-out container 6008. Alternatemethods of cleaning or drying (e.g. radiation from a heating lamp, anitrogen gas blower and the like) can also be employed for the samepurpose.

Plating of material 6002 takes place in plating bath 6011 in the secondtank 6014, either galvanostatically or potentiostatically, usinggalvanostat/potentiostat (or voltage source) 6010. Material 6002 to beplated can be biased negatively relative to voltage source 6010 usinggrounded contact 6009. A counter electrode/contact 6012 can be biasedpositively directly from voltage source 6010. Both contacts 6009 and6012 have ends positioned in second tank 6014 containing plating bath6011 in order to contact material 6002. Pulse plating, which is wellknown to those skilled in the art, also can be used. After exitingsecond tank 6014, a third tank (not shown) can be used to rinse theplated material before it is re-wound on take-up reel 6003.

It is noted that FIG. 24 shows two power supplies—one power supply toapply pulses 6006 to material 6002 received from supply reel 6001 whilein the first tank 6005, and a second power supply to supply requiredplating voltages/currents while material 6002 is in second tank 1014.The procedure in first tank 6005 removes the inhibiting film makingmaterial 6002 sufficiently clean to make plating possible in the secondtank 6014.

Additional examples of cell arrangements and plating/etching processesfor substrates having inhibiting surface films are described herein withreference to FIGS. 26-31.

FIGS. 26 and 27 show plating/etching cell arrangements 1800 and 1900 forindividual substrates and long lengths of wire or sheet flat stocksubstrates, respectively. With reference to FIG. 26, in cell arrangement1800, individual substrate 1803 and counter electrode 1804 are mountedfacing one another and immersed in electrolyte 1805. A voltage source1806 is connected across counter electrode 1804 and individual substrate1803, which serves as a working electrode. For plating or depositionprocesses, the negative pole of voltage source 1806 can be connected tosubstrate/working electrode 1803. Conversely, for etching processes,depending on the electrolyte used, either the positive pole or thenegative pole of voltage source 1806 can be connected to thesubstrate/working electrode 1803. Voltage source 1806 is configured togenerate both high and low voltage pulses. In operation, a high voltagepulse (or a series of pulses) is followed by a low cw or modulatedvoltage signal for a period of time which is determined by the desiredthickness of deposition or depth of etching.

The high voltage and low voltage pulses are applied betweensubstrate/working electrode 1803 and counter electrode 1804. (See FIG.26). First, a high voltage pulse 1801, which is on the order of20-2000V, is applied so that a current of at least about 120-200 A/cm²flows between substrate/working electrode 1803 and counter electrode1804. High voltage pulse 1801 can have a full width at half maximum onthe order of 10 ns to 1 s. These voltage and current parameters for highvoltage pulse 1801 correspond to energies of at least 5-14 Joules/cm²delivered to substrate/working electrode 1803. Application of highvoltage pulse 1801 results in removal of the inhibiting oxide or film onsubstrate/working electrode 1803. Next, a low voltage pulse 1802 on theorder of 0.01-5 volts is applied between substrate/working electrode1803 and counter electrode 1804. Low voltage pulse 1802 can have a pulsewidth of about 1 second, and can be modulated using suitablemicroprocessor or digital data processing device coupled to voltagesource 1806. The application of low voltage pulse 1802 is designed toactivate the desired electrolytic plating or etching processes on thesurface of substrate/working electrode 1803.

With reference to FIG. 27, cell arrangement 1900 is configured with areel-to-reel material handling system for long length wire or sheet flatstock substrate 1903. The reel-to-reel material handling system includesa supply reel 1901 and a take-up reel 1902 on which unprocessed andprocessed substrates 1903 are respectively wound. Substrate 1903, whichfunctions as a working electrode, passes through electrolyte 1907 facingsplit counter electrodes 1904 and 1905. Voltage source 1908 is connectedacross substrate/working electrode 1903 and counter electrodes 1904 and1905. Voltage source 1908, which like voltage source 1806 is capable ofgenerating both high and low voltage pulses, can have a low voltageterminal, a high voltage terminal and a common terminal. The highvoltage and low voltage terminals of voltage source 1908 are connectedto counter electrodes 1904 and 1905, respectively, while the commonterminal is connected to substrate/working electrode 1903.

In operation, voltage source 1908 generates high voltage pulses 2001 andlow voltage pulses 2002 for reel-to-reel plating of substrate 1903. (SeeFIGS. 27 and 29). High voltage pulses 2001 are applied across counterelectrode 1904 and substrate/working electrode 1903. A high voltagepulse 2001 (or a series of pulses), like high voltage pulse 1801, isdesigned to result in removal of the inhibiting oxide or film on theportion of substrate/working electrode 1903 facing electrode 1904. Eachhigh voltage pulse 2001 can only be on for the order of at most a fewmilliseconds. Low voltage pulses 2002, which can be cw or modulated cwsignals, are applied across counter electrode 1905 and substrate/workingelectrode 1903 to portions of substrate 1903 that have traveled fromfacing electrode 1904 to facing electrode 1905. Low voltage pulses 2002can be continuous wave or modulated low voltage pulses that are designedto activate the desired plating or etching processes. With thisarrangement, high voltage pulses 2001 can be applied with a repetitionrate of “L/v” seconds, where L is the length of counter electrode 1904,and v is the linear travel speed at which substrate/working electrode1903 is pulled through electrolyte 1907 across electrode 1904 andelectrode 1905. The linear travel speed v can be adjusted so that lowvoltage pulses 2002 are applied across electrode 1905 to a portion ofsubstrate/working electrode 1903 within less than a second after theapplication of high voltage pulse 2001 across electrode 1904 to the sameportion of substrate/working electrode 1903. The durations of lowvoltage pulses 2002 can be selected upon consideration of length ofcounter electrode 1905 and the rate of deposition or etching, which ratein turn depends on the type of electrolyte 1907 used for plating oretching and the type of substrate/working electrode 1903. In practice,the durations of low voltage pulses 2002 can be on the order of at leastseveral seconds, which is comparable to the time it takes forsubstrate/working electrode 1903 to travel across electrode 1905.Additionally, low voltage pulses 2002 can remain on concurrently withhigh voltage pulses 2001, or alternatively can be interrupted for thedurations of high voltage pulses 2001 that are of the order of at most afew ms.

FIG. 30 shows another etching/plating cell arrangement 2200 foretching/plating of substrates with inhibiting surface films. Cellarrangement 2200 is advantageously configured for processing athree-dimensional substrate 2209. Cell arrangement 2200 uses anelectrolyte jet stream 2208 to etch or plate the surfaces of substrate2209, which is held by an electrically conducting robotic arm 2210. Avoltage supply 2216 is connected across substrate 2209 and electrode2205 disposed in an electrolyte-holding pressure cell 2204. Electrode2205 serves as an anode and a cathode for plating and etching processes,respectively. Electrolyte jet stream 2208 is generated fromelectrolyte-holding pressure cell 2204 and directed by nozzle 2207 on tosubstrate 2209. Further, nozzle 2207 can have a diameter in the range offrom 100-10,000 microns for typical applications. Electrolyte 2213 ispressurized into jet stream 2208 through nozzle 2207 by pump 2214, whichforces electrolyte 2213 from reservoir 2212 into pressure cell 2204.Electrolyte 2213 flows into pressure cell 2204 through an opening inelectrode 2205, which for electroplating processes is connected to thepositive polarity of voltage supply 2216. Different portions of thesurfaces of substrate 2209 are presented to jet stream 2208 forprocessing by movement of robotic arm 2210 under the control of roboticcontrol system 2211 and digital data processing device 2215.

Cell arrangement 2200 further includes provisions for modifying thefree-standing jet plating or etching processes with an electromagneticenergy beam (e.g., an intense laser beam) directed collinearly along jetstream 2208. For this purpose, cell arrangement 2200 includes a pulsedlaser 2210 which generates a laser beam 2202. Pulsed laser 2210 isaligned so that laser beam 2202 passes through window 2203 into pressurecell 2204 and then through electrode 2205 along nozzle 2207. On exitingpressure cell 2204, laser beam 2202 is guided by jet stream 2208 whichacts as a wave guide or light pipe causing laser beam pulse 2202 and jetstream 2208 to travel collinearly. This wave guide or light pipearrangement permits laser beam pulse 2202 and jet stream 2208 to beincident collinearly on surface portions of substrate 2209 presented forprocessing. Modification of electroplating and etching processes with anintense laser beam have been described, for example, in U.S. Pat. No.4,497,692.

In cell arrangement 2200, a pulsed laser 2201 produces a set of one ormore pulses 2202 of laser light for a total time on the order of 1 ps to10 ms. The set of pulses 2202 is preferably triggered immediately aftera new portion of the surfaces of substrate 2209 is presented to jetstream 2208 for processing by movement of robotic arm 2210. The pulsingof laser 2201 can be coordinated with the movement of robotic arm 2210by digital data processing device 2215 which is interfaced with therobotic arm control system 2211.

In operation, laser pulses 2202 incident on substrate 2209 can beconfigured to have a power density on the order of 10⁵ to 10¹⁰ W/cm² inorder to remove the inhibiting films from the surfaces of substrate2209. Each laser pulse 2202 can have a pulse width or duration on theorder of about 10 ps to 10 ms, and have a fluence of 1-5,000 mJ/pulse.These parameters can be selected on consideration of the cross sectionalarea of jet stream 2208 as well as the thermal properties of sample 2209and the coatings thereon.

While laser 2202 is operated in a pulsed mode, jet stream 2208 can beoperated in a continuous mode (cw) to activate the desired plating (oretching) processes on the surface of sample 2209. The desired plating oretching can occur after the inhibiting surface films have been removedby application of the high intensity laser pulses 2202. Robotic arm 2210can move substrate 2209 so that any surface portion of 2209 can beplated (or etched) as determined by digital data processing device 2215,which synchronously controls robotic control system 2211 and the pulsingof laser 2201. In some embodiments, laser 2202 can be programmed so thatafter emitting a high intensity pulse 2202 that removes the inhibitingsurface films, the laser emission drops to a much lower power level toinduce laser-enhanced jet plating or etching as is well known in theliterature.

FIG. 31 shows another cell arrangement 2300 for modification ofelectroplating and etching processes with an intense laser beam. Cellarrangement 2300, like cell arrangement 2200, includes pulsed laser2201, digital data processing device 2215, voltage supply 2216, and adigital data processing device controlled robot 2211 having anelectrically conducting robotic arm 2210 for mounting substrate 2209 inelectrolyte 2213. However, electrolyte-holding cell 2206 and nozzle 2207of cell arrangement 2200 shown in FIG. 30 are replaced in cellarrangement 2300 by an insulating flexible curtain 2301, which defines avolume 2303 of electrolyte 2213. Flexible curtain 2301 preferably has aconical shape. Flexible curtain 2301 includes an inside electrode insertor extension 2302. Electrode 2302, which can be made of small strips ofelectrically conducting material, is disposed in curtain 2301 in closeproximity to substrate 2209. Voltage supply 2216 is connected acrosselectrode 2302 and substrate 2209 with a suitable polarity orientationfor either electrolytic plating or etching as desired.

In operation, different surface portions of substrate 2209 are movedunder electrolyte volume 2303 by movement of robotic arm 2210 under thecontrol of digital data processing device 2215. Like in the operation ofcell arrangement 2200, pulsed laser 2201 generates a high intensitylaser pulse (or a series of pulses) to remove inhibiting surface filmsfrom substrate 2209. The high intensity laser pulse, which can have aduration of a few picoseconds to milliseconds, is directed inside thevolume of curtain 2301 on to substrate 2209 to remove inhibiting surfacefilms from surface portions of substrate 2209 under electrolyte volume2330. As described with reference to FIG. 30, the desiredplating/etching of substrate 2209 can occur after the inhibiting surfacefilms have been removed by application of the high intensity laserpulse. Robotic arm 2210 moves substrate 2209 so that any surface portionof substrate 2209 can be plated (or etched) as determined by digitaldata processing device 2215, which synchronously controls roboticcontrol system 2211 and the pulsing of laser 2201.

The movement of substrate 2209 caused by robotic arm 2210 results incurtain 2301 being slid along the surface of substrate 2209. Curtain2301 can have small holes to allow electrolyte 2213 to recirculatethrough volume 2303. Alternatively, an auxiliary pump (not shown) can beused to maintain a desired level of electrolyte 2213 inside volume 2303that is defined by conically shaped flexible curtain 2301.

The foregoing merely illustrates the principles of the disclosed subjectmatter. Various modifications and alterations to the describedembodiments will be apparent to those skilled in the art in view of theteachings herein. It will be appreciated that those skilled in the artwill be able to devise numerous modifications which, although notexplicitly described herein, embody the principles of the disclosedsubject matter and are thus within its spirit and scope. For example, itwill be readily understood by those skilled in the art that theremoval/plating processes, which utilize two tanks with their respectivebaths, can also be used for individual pieces of material without theuse of the reel-to-reel material handling system described withreference to FIGS. 24 and 25. In such case, a means of dipping thesamples serially into the two tanks can be used instead of thereel-to-reel system.

Further, for example, the native oxide or inherent inhibiting layer onthe substrate surface can be used as the equivalent of a contact mask incombination with the laser. The laser removes the portion of the oxideor inhibiting layer permitting plating or etching to occur in just thoseregions where the laser has removed the inhibiting layer. The plating oretching as well as the removal of the inhibiting layer or oxide can alloccur in situ, i.e. within the plating or etching bath. The laserremoves the oxide and thereby provides a maskless pattern on thesubstrate surface in preparation for plating by way of exchange (alsoknown as immersion) plating. Here the laser pulse opens up the oxidewhile the sample is in the electrolyte. Once the oxide has been removedlocally, exchange plating can occur, leaving a very thin layer of themetal in the electrolyte as a deposit on the substrate. During thisportion of the operation, there is no potential applied and the exchangeor immersion plating leaves a uniformly thin film on each of the areasopened up (oxide removed) by the laser. After that, electroplating orelectroless plating can be made to occur on all the thin layers of nearequal thickness resulting from the laser pulse and the immersion so thatthe entire pattern has a resulting uniform thickness. Similarly, theoxide surface layer can be removed by application of high voltagedischarge pulse. Again, immersion plating can be allowed to take placefollowed by standard electroplating to increase the thickness of theimmersion layer. Thereafter, a voltage can be applied to provideadditional plating in the openings caused by voltage pulse that was usedto build up the immersion plated layer.

The plate-up of the exchange plated layer can take place in the samebath in which oxide removal occurred or in a second bath. The secondvoltage used for plating/etching, which can be continuous or in the formof repetitive pulse, can have an amplitude on the order of about +/−1-3V. For galvanostatic plating/etching, the second voltage pulse amplitudecan be considerably higher depending, for example, on sample size.

In laboratory demonstrations, electroplated patterns of copper onstainless steel 316 substrate have been obtained by first patternmasking the substrate, then applying a voltage pulse to remove surfaceoxides in the mask openings followed by plating. FIG. 32 shows anexemplary substrate 24-103 used in the laboratory demonstrations. Anelectrically insulating patterning mask 24-104 is formed on substrate24-103 so that regions 24-102 are electrically insulating and thereforeare not be subject to surface oxide removal and plating/etching. Theexposed mask opening regions 24-104 are subject to surface oxide removaland plating/etching. FIG. 33 b shows a masked substrate 25-201 disposedin an electrolyte 25-203 facing immersed counter electrode 25-202. Apower supply 25-204 is configured to apply potential pulses acrosselectrodes 25-202 and 25-203 immersed in the electrolyte. FIG. 33 ashows an exemplary high voltage pulse 25-205, which is applied to removesurface oxide layers from regions 24-104. Exemplary high voltage pulse25-205 can, for example, be on the order of 20 V or greater, and have apulse width of about 1 ms. After the surface oxide removal pulse 25-205,power supply 25-204 can be used to apply lower voltage pulses (e.g.,25-206) for plating or etching action on the “prepared” oxide-freesurface regions 24-104.

FIG. 34 shows another view of the electrolytic cell and electrodearrangement of FIG. 33 b used of plating. For plating action, thenegative polarity of supply 26-204 is connected to substrate 26-201(24-103). A small voltage on the order of about 2.0 V is applied betweensubstrate 26-201 and counter electrodes 26-202 for plating etching ofoxide-free regions 24-104. After completion of the plating process, themask material can be conventionally removed (e.g., by stripping,dissolving, ashing, etc.) leaving a pattern of plated material inregions 24-104 on substrate 24-201. It will be understood that the samemasking technique can be used for patterned etching in regions 24-104 onsubstrate 24-201.

In an exemplary embodiment illustrated in FIG. 35, in-situ laserablation of an oxide coated metal (e.g., aluminum) is performed in afirst bath, resulting in patterned immersion plating of the first cationin the first bath. The in-situ laser ablation is followed by a firstplate-up of the thin immersion plated pattern. This first plate-up canbe followed by a second plate-up in a second bath to plate a secondcation onto the first plated deposition. This can cause good adhesion ofthe second deposited cation, especially when the substrate is aluminumand the second cation is tin. In one embodiment using aluminum,immersion copper or immersion nickel in the first bath is plated upafter ablation while the second bath can be a tin electrolyte. On theother hand a second bath can be avoided if the desired deposit can existby plating-up in the first bath. For example, local oxide removal by wayof a laser pulse can occur on aluminum in a copper bath while no currentis applied. The immersion plating that results is then plated up (byelectroplating) in the same copper bath.

As another example, it can be desired to plate nickel onto aluminum,then plated up by tin. In that case, the laser can be applied to theoxide coated aluminum in nickel bath, the portions of the oxide removedfrom the sample then electroplated-up by nickel followed byelectroplating (or electroless plating) in a tin bath. This techniquecan be used with a reel-to-reel system since it allows patterning tooccur which will have equal thicknesses when the immersion plating isperformed before any electroplating occurs since the immersion platingis self limiting and normally stops after a deposit ˜20-50 nm thickness.The plate-up can begin after the patterning by immersion plating iscomplete so that the entire electroplated pattern will have uniformthickness.

The above technique (after laser ablation) can be used for a single ormultiple plating pattern (when immersion plating occurs first) to definethe pattern. Then, after the immersion plating has taken place, the samebath can be used to electroplate the immersion pattern resulting inuniform thickness of the entire pattern.

Another method for a reel-to-reel plating system, as shown in FIG. 36,is to use a scanning mirror in combination with the movement of thesubstrate from one of the two or more reels. This combination can beutilized when the laser has a high repetition rate. Without thatcombination, the laser beam is incident on the moving substrate but thebeam exiting the laser remains in a fixed position on the movingsubstrate thereby causing boiling of the electrolyte to occur. When thathappens, the contact of the beam on the substrate is either distorted orcompletely lost even though the electrolyte can be circulated.

It therefore is a part of the disclosed subject matter to include, incertain embodiments, a scanning mirror pattern that results indistributing the beam spatially while still contacting the movingsubstrate as it passes through the electrolyte. In an exemplaryembodiment, the total area covered by the scanning beam can be as smallas 2×2 cm.

FIG. 37 shows another reel-to-reel plating system utilizing a two bathsystem: an immersion plating bath and a standard electroplating bathseparated by a partition. The sample to be plated can be supplied fromthe supply reel and can be moved between the baths by means of thereel-to-reel system. The sample can be an aluminum sample, sized(thickness) on the order of, for example, tens of mils. Also shown isthe electrolyte supply tank for supplying a sheath of electrolyte ontothe surface of the sample as it exits the supply reel. The sheath ofelectrolyte can be a thin sheath, e.g., on the order of 50 to 1,000microns, which can be sufficient for immersion plating of variousmaterials, including copper, nickel and tin. The electrolyte can bere-circulated by the use of a re-circulation duct and a circulation pumpand water can be added to the immersion bath when re-circulation isutilized to compensate for the effects of evaporation.

FIG. 37 further shows the immersion plating after oxide removal of thesample. This can be accomplished utilizing a laser transmitted into theimmersion plating bath through a lens and a window in the immersionbath. In an exemplary embodiment, the lens can be a long focal lengthlens, having, for example, a focal length greater than 30 cm. The windowin the immersion bath can be made out of, for example, glass orsapphire, or any other material with good transparency characteristics.Due to splashing that can occur during ablation the long focal lengthlens can be utilized to allow for a greater distance between the sampleand the transparent wall, thus preventing the window or the lens fromgetting the splashed droplets on the surface. As shown in FIG. 29 thesample can be transferred to the standard electroplating bath forelectroplating after it has been immersion plated.

FIGS. 38-40 show systems and methods for plating or etching a wire onmore than one side. FIG. 38 is a perspective view of a sample wire witharrow depicting the laser light directed onto the wire from fourdirections and a fifth arrow depicting the direction of travel of thewire.

FIG. 39 shows a system and method for four sided oxide ablation of awire sample using a single laser to achieve immersion plating. As shownin FIG. 39, the sample wire can be immersed in an immersion tank withfour transparent windows or four transparent walls or any combinationthereof, which can be made out of glass or sapphire, for example. Theimmersion tank can be contain an electrolyte for the purposes ofachieving immersion plating in reaction to the laser light beingincident upon the wire sample. The wire sample can be moved to astandard plating tank for electroplating, using, for example, areel-to-reel system. In the same or another embodiment, the wire samplecan be attached to a sliding contact and a counter electrode can residein the immersion tank to achieve electroplating in the immersion tankitself.

In an embodiment shown in FIG. 39, the immersion tank can be surroundedby seven mirrors, numbered 1-7, wherein mirrors 1, 3 and 5 are partiallytransparent mirrors and mirrors 2, 4, 6 and 7 are totally reflectivemirrors. However, it is envisioned that the mirrors 1-7 could be of avariety of transparencies and none are restricted to being totallyreflective. The laser beam emitted from the laser can be directed firstto mirror 1, then proceed to be reflected and/or transmitted by each ofthe remaining mirrors sequentially, thereby achieving laser irradiatingof the wire sample from at least four different directions. In oneembodiment, the mirrors 1-7 can be positioned such that the incidentlaser paths are separated by a 90 degree angle each, thus irradiatingthe wire sample evenly from four sides. FIG. 39 further shows fourlenses positioned between each of the incident laser paths and the wiresample. In an exemplary embodiment, the lenses can be cylindrical lensescapable of transforming the laser spot into a laser line lying along thelength of the wire sample; however, it is envisioned other types oflenses could be used, for example, spherical lenses.

FIG. 40 depicts an exemplary embodiment for a system and method for foursided oxide ablation of a wire sample using two lasers, laser 1 andlaser 2, to achieve immersion plating. Similar to the above, the wiresample can be immersed in an immersion tank with four transparentwindows or four transparent walls or any combination thereof, which canbe made out of glass or sapphire, for example. The immersion tank can becontain an electrolyte for the purposes of achieving immersion platingin reaction to the laser light being incident upon the wire sample. Thewire sample can be moved to a standard plating tank for electroplating,using, for example, a reel-to-reel system. In the same or anotherembodiment, the wire sample can be attached to a sliding contact and acounter electrode can reside in the immersion tank to achieveelectroplating in the immersion tank itself.

In an embodiment shown in FIG. 40, there can be six mirrors numbered 1-6configured around wire 7 (oriented perpendicular to the plane of thefigure) and cell 8, wherein mirrors 1 and 4 can be partially transparentand mirrors 2, 3, 5 and 6 can be totally reflective. However, it isenvisioned that the mirrors 1-6 could be of a variety of transparenciesand none are restricted to being totally reflective. The laser beamemitted from laser 1 can be directed first to mirror 1, wherein aportion of the laser is transmitted through mirror 1 and the remainderis reflected to mirror 2 then mirror 3 then incident upon the sample.The laser beam emitted from laser 2 can be directed first to mirror 4,wherein a portion of the laser is transmitted through mirror 4 and theremainder is reflected to mirror 6 then mirror 6 then incident upon thesample. In one embodiment, the mirrors 1-6 can be positioned such thatthe incident laser paths are separated by a 90 degree angle each, thusirradiating the wire sample evenly from four sides. In an exemplaryembodiment, the lasers 1 and 2 can be synchronized. FIG. 32 furthershows four lenses positioned between each of the incident laser pathsand the wire sample. In an exemplary embodiment, the lenses can becylindrical lenses capable of transforming the laser spot into a laserline lying along the length of the wire sample; however, it isenvisioned other types of lenses could be used, for example, sphericallenses.

FIG. 41 shows a side perspective view of a reel-to-reel system of theembodiments of FIGS. 39 and 40. A laser, one of the cylindrical lensesand wire sample are shown. Also shown is the immersion plating tank andthe direction of travel of the wire sample is illustrated as well. Notshown are the various mirrors and beam splitters, e.g., semitransparentmirrors.

FIG. 42 depicts an exemplary embodiment for a system and method for twosided oxide ablation of a ribbon or wire sample using a single laser toachieve immersion plating and/or maskless-etching using a single laser.FIG. 42 shows an embodiment utilizing a reel-to-reel system inconjunction with four mirrors, numbered 1-4. The laser can be directedat mirror 4, which can be partially transparent, thus permitting aportion of the laser beam to be incident upon a first side of thesample, achieving laser ablation of an oxide layer on the first side.The portion of the laser beam that is reflected from mirror 4 can thenbe reflected between mirrors 1, 2 and 3, thus being incident on a secondside of the sample, achieving laser ablation of an oxide layer on thesecond side. FIG. 42 further shows that between mirror 4 and a firstside of the sample can be a first lens and between mirror 3 and a secondside of the sample can be a second lens. Though FIG. 43 depicts thereflected path of the laser beam traveling in the vertical directionrelative to the sample, it is envisioned that the mirrors 1-4 could bepositioned such that the beam traveled along any suitable path to resultin being incident upon another side of the sample.

FIG. 42 also shows that on two sides of the sample there can be apartition, each of which can either be made of a transparent material,e.g., glass or sapphire, or can contain windows, which also can be madeof glass or sapphire, for example. One partition can also form a wall ofan immersion plating and/or standard electroplating bath. The twopartitions can together form a channel for channeling an electrolytefluid layer along two sides of the sample. The sample can be fed from asupply reel through the narrow channel, thus allowing for an electrolytefluid layer to be deposited on two sides of the sample. A re-circulationduct connected to a pump can be used to re-circulate the electrolytefluid, re-depositing the fluid into the narrow channel.

As shown in FIG. 42, the sample can be connected to a voltage source atthe supply reel by means of a sliding contact. The sample can beelectroplated by passing it between two anodes contained in theelectroplating bath and connected to the voltage source. The sample canthen be transferred to a rinse bath (not shown) by utilizing thereel-to-reel system. An exemplary embodiment represented in FIG. 42 canalso be used to achieve maskless-etching by reversing the polarity ofthe electrodes connected to the voltage source, thus the laser ablationof the two sides removes an oxide layer from the two sides and those twosides can be etched by passing the sample between the two cathodesimmersed in the bath.

FIG. 43 depicts a side view showing the feeding of the sample of theabove embodiment into the channel formed by the two partitions. FIG. 35further illustrates the flow of the electrolyte fluid layer into thechannel formed by the two partitions and a region of laser incidence isillustrated as well.

Unless specified otherwise, the aforementioned methods and systems thatemploy light sources (e.g. lasers) to remove naturally formed metaloxides for in situ plating or etching can function based on thermal ornon-thermal means. Generally, thermal mechanisms are often consideredthe main mechanism for metal oxide removal, and the embodimentsdescribed above have focused on thermal means.

In certain embodiments, however, laser radiation that utilizes photonsresult in the in situ non-thermal or near non-thermal (e.g. around 193nm, or lower) removal of the oxide is employed in conjunction with anyone of the methods and systems described in this application.

Advantages of non-thermal or near non-thermal oxide removal include 1)minimal deformation of the oxide coated substrate to be plated bylimiting the accompanying shock wave due to otherwise thermal heatingand 2) the oxide can be removed with a minimal removal of substratematerial. Generally, the energy/area or fluence to remove an oxide isconsiderably less than that required to remove the metal itself.

Since the oxide removal utilizes systems of ablation that eliminate orgreatly reduce thermalization or heating, melting can be minimized.Thus, the substrate can maintain its smooth surface contour, importantin many plating applications.

In one embodiment, the amount of substrate material removal resultingfrom ablation can be far less than 1 micron in material depth. Forexample, A. V., Rode et al, Applied Surface Science 254, 3137 (2008),which is hereby incorporated by reference, describes the removal of 14nm/pulse of copper under certain focusing conditions using femtosecondlaser pulses, one of the mechanisms proposed herein. While not beingbound by any particular theory, it is believed that in both UV laserablation and femtosceond laser ablation, there is little thermalizationbetween the excited electrons and the much heavier protons of theabsorbing layer so that the electrons assume an antibonding state. As aresult the atom in of the thin film ablates, vaporizes or disintegratesdue to instability in a non-thermal manner.

A similar process is described by Haight et al in J. Vac. Sci.Technology B17, 3137 (1999), hereby incorporated by reference, in whichfemtosecond laser pulses are used to ablate a very thin film or layer ofmisplaced chromium metal on a glass mask. The non-thermal ablatingprocess, using a femtosecond laser, restores the mask to its desiredpattern without any damage to the underlying glass. If the glass were tobe damaged by the metal removal, the mask would become worthless.

Two laser processes are described herein that can achieve non-thermal ornear non-thermal oxide removal: 1) photo ablation using UV laser pulseor pulses and 2) femtosecond laser pulses. The first process, photoablation with UV, uses a wavelength that causes an electron to be raisedto an ionization level causing the atom or molecule to disintegrate.This ‘photoablation’ mechanism has been described in detail in numerouspapers. See, e.g., A. V. Kabashin and M. Meunier, Femtosecond laserablation in aqueous solutions: a novel method to synthesize non-toxicmetal colloids with controllable size, Journal of Physics:ConferenceSeries 59, 354 (2007); B. Wolff-Rottke, J. Ihlemann, H. Schmidt, and A.Scholl, ‘Influence of the laser-spot diameter on photo-ablation rates’,Appl. Physics A60, 13-17 (1995); J. Ihlemann, ‘Patterning of oxide thinfilms by UV-laser ablation,’ Journal of Optoelectronics and AdvancedMaterials 7, 1191 (2005); J. Ihlemann, A Scholl. H. Schmidt, B.Wolff-Rottke, ‘Nanosecond and femtosecond excimer-laser ablation ofoxide ceramics’ Appl. Phys. A60, 411 (1995); and J. Ihlemann, K. Rubahn,Excimer laser micromaching: fabrication and applications of dieletricmasks, Applied Surface Science 154-155, 587 (2000), each of which ishereby incorporated by reference in their entirety.

Depending on the uv wavelength, i.e. whether, for example, deep UV ordeep near UV, i.e. 193 nm (excitation of gaseous ArF) to 306 nm(excitation of XeCl gas) respectively, the ablating mechanism can be,respectively, electronic and partly thermal or purely electronic.Fluences for this type of ablation are generally in the range 1-10J/sq-cm, readily available from commercial lasers.

The second method is the use of very short pulses, typically in thefemtosecond range, or alternatively in the picosecond range. Here thephonon-phonon and phonon-electron mean free paths, or more precisely thetimes for collisions to cause thermalization are considerably longerthan the pulse duration so that the thermal diffusion cannot be used toexplain either the material removal or the depth of thermal diffusion.Generally, such ablation is described in terms of multiphoton absorptionwhich is closely related to the use of deep UV pulses. The multiphotonabsorption causes sufficient excitation of the absorbing electron tolead to disintegration of the material.

In certain embodiments, uv pulses or the femtosecond pulses can also beutilized for in situ oxide removal in solution where the solution can beabsorbing or where the laser can adversely affect the stability of thesolution. In such embodiments, interactions between the solution andlaser can be overcome for both UV and femtosecond ablation by using aminimum depth of solution over the material. This can be provided, forexample, by continuous spraying of the solution on the material with theoxide layer to be removed or by having a thin layer of solution flowingover the substrate to be plated in the region where the laser isincident.

In one embodiment, excimer lasers are directed into various liquids,such as electrolytes, to achieve ablation of the oxide surface layers.Their use should be analogous to the use of pulsed visible lasers.However the use of femtosecond lasers in that mode could, in certaincircumstances, not be ideal as there can be strong interaction betweenthe femtosecond light and liquids. However, it is disclosed as anexemplary embodiment where the ablation takes place in an inert gasafter which the substrate is then rapidly transferred into theelectrolyte for plating. This embodiment is particularly suited for theuse of fs lasers for oxide removal followed by plating/etching (see FIG.48 of this application, discussed below).

Generally, it is preferable that one know the transmission spectrum ofall the intended electrolytes, including sulfuric acid which can be usedfor the initial ablation, followed by rapid transfer to the desiredplating solution. For example, the transmission of technic silver, goldand tin are about 100% transmitting from deep uv (about 200 nm to about1 micron). Deterioration of tin solution has been observed with the useof ns laser pulses to remove the oxide from Al. Since the solution isessentially transparent over the wavelength range 200 to 900 nm, it islikely that the deterioration is due to the heating at thesolution/substrate interface. It is therefore likely that the use ofeither uv (photoablation) or femtosecond pulses to remove the oxide willnot result in this degradation.

There are a number of excimer lasers that have strong output in theultraviolet, from about 157 to 351 nm. There also cw UV lasers andpulsed solid state lasers but the UV from those is generallyconsiderably smaller in intensity and smaller in fluence that thatobtainable from excimer lasers. There also exist a large numberfemtosecond lasers with very high intensity and therefore largefluences. For example one mJ at 50 fs translates to a power of 2×10¹⁰ W,which when focused to 1 sq mm generates a fluence 2×10¹² W/cm². All ofthese lasers can be used for the removal of oxides in situ withoutcausing substantial heating.

For example, to remove aluminum oxide requires, in certain embodiments,on the order of ˜1 J/cm² which is readily obtained with a 193 ArF laserwhere the unfocused output pulse is on order of 100 mJ with a repetitionrte of 50 Hz (Coherent Complex Pro series). Similarly, the commerciallyavailable Coherent KrF Complex Pro series has an output of 150 mj/pulse,at 50 pps. For both of these lasers, oxide layers can be removed at highspeeds. With the KrF laser focused to 0.2 square centimeters, it is thenpossible, with a single pulse, to remove 0.75 sq-cm of oxide in situ,with little substrate heating or ˜35 sq cm/s.

To remove an oxide from a metal in situ for subsequent plating oretching, the lasers for oxide removal can be scanned over the materialusing methods known by those of ordinary skill in the art. For example,in a reel to reel system, the motion of the substrate between the reelsresults in at least partial scanning without further accessories. Othermethods utilize scanning mirrors or rotating mirrors to direct the laserto desired parts of the substrate.

Shown in FIG. 44 is a UV or femtosecond laser 100 with beam 103 aimedthrough lens 102. The lens can be spherical, cylindrical, with apositive or negative focal length, generally depending on the intensityof the laser. The beam traverses into electrolyte 107 and in is directedto the oxide coated metal 106. Plating or etching can than occur in situby applying the appropriate current/potential to power supply 101.

In order for the laser in situ processing to be effective, it isnecessary to have the sample reside in an electrolyte that is reasonablytransparent (e.g. 240 nm pulses in a nickel Watts bath) to the laser tobe used for oxide removal. For purposes of illustration, curves takenwith a spectrophotometer using a 1 cm cuvette are shown for a standardcopper sulfate electrolyte and a nickel sulfate solution (Watts bath),in FIG. 45. In certain embodiments, absorption is on the order of, orless than 20% per centimeter.

It can be seen from the curves of FIG. 45 that in terms of the lasertransmission, a UV laser would be suitable for use with a Watts (Ni)bath in the range around 248 nm, the wavelength of the KrF excimer (gas)laser. For a copper solution, it may be necessary to assure that thefluid over the substrate be only on the order of, for example 1 mm inthickness to assure adequate transmission if 248 nm onto the oxidecoated metal substrate since the copper is relatively strongly absorbingat ˜250 nm range. Based on the foregoing discussion, and knowledge ofone of ordinary skill in the art, the individual approach can bedetermined for the particular electrolyte based on the selected lightsource.

From these curves, it is clear that UV lasers in the range ˜250 nm wouldbe suitable for in situ oxide removal in a Watts solution where, forexample a KrF excimer laser at 248 nm would have a suitable wavelength,since it is substantially transparent at this wavelength as seen in FIG.45.

FIG. 45 is a set of transmission curves for Sn, Au and Ag indicatingalmost complete transmission over the range 300-900 nm. This range fitswell into the femtosecond pulses generally available in the 750-800 nmrange. Therefore such electrolytes are useful for the in situ oxideremoval without generating substantial heating for those oxide coatedsubstrates requiring Sn, Au or Ag plating. The absence of substantialheating means that the solutions will not degrade at the metal-solutioninterface as has been observed for tin plating on oxide coated metalsusing nanosecond pulses of 532 nm.

FIG. 46 shows the transmission for a 1.8 M solution of sulfuric acid.This solution can be used in cases where either the entire substrate isfully immersed during ablation of its oxide coating or where the oxideis fully wetted by sulfuric acid. In either case, a UV or femtosecondlaser is not substantially absorbed by the solution transparent to thesolution and very little or no heating can be made to occur during theablation process using either UV or femtosecond lasers. After ablation,the substrate is removed and immersed in the appropriate platingsolution. This can only be done where the small amount of acid thatadheres to the substrate does not substantially contaminate the plating(or etching) electrolyte.

FIG. 48 shows an exemplary way in which an inert gas can be used to overpressure a tank connected to a plating bath for a reel to reel in situablation/plating/etching system. There is shown that a wire or flatstock 504 from a supply reel (not shown) is introduced to a quartz orglass tank 505, in which the sample is ablated using a femtosecond orultraviolet pulsed laser 100. The tank is pressurized with an inert gas(e.g. argon). After exiting the ablation tank 505, the substrate isintroduced to a plating bath 509 via flap opening 506. The plating bathcontains an electrolyte solution (e.g. nickel sulfate) and counterelectrode 507, which receives current from current supply 101. The inertgas is supplied at a pressure that is at least slightly greater than thehead pressure of the plating bath, thus preventing oxidation fromoccurring in the glass tank 505, and preventing liquid from entering thetank through flap opening 506. To the extent that it is desired toreduce bubbling of the liquid in the plating batch 509, this embodimentcan be modified to include intermediate tanks located between theablation tank 505 and the plating bath 509.

In one particular embodiment, which can be used in conjunction with anyof the above described methods and systems, a process is provided toprevent unwanted depositions, if any, in areas not subjected to thelaser energy. This has been discussed in Ref: T. Kikuchi, S. Z. Chu, S.Jonishi, M. Sakairi, and H. Takahashi, Electrochim. Acta, 47, 225(2001), which is hereby incorporated by reference in its entirety. Theseauthors used an additional oxidation step to increase the thickness ofthe natural oxide in order to reduce/eliminate unwanted plating.

In certain embodiments of the present application, however, thepresently disclosed subject matter proposes a different solution toprevent unwanted depositions in areas not subjected to the laser energyproblem by introducing a source of steam in the reel to reel platingsystem. It is known that steam causes oxidation of aluminum and othermetals (see for example U.S. Pat. No. 5,496,417. Certain embodimentsemploy steam, incident on the surface of the Al or other oxide coatedmetal to be plated, to increase the thickness of the natural oxidecoating. The laser fluence for removing the oxide is then adjusted toenable removal of the thicker oxide in designated areas on the metal tobe plated/etched. Due to the enhanced thickness, random plating canbecome much less likely if it occurs at all. The use of steam is cheaperand much more rapid as a means of enhancing oxidation, hence increasingoxide thickness, than the use of electrochemical anodizing as proposedin the above cited reference by Kikuchi et al.

The steam can be introduced in the early stages of a reel to reelplating system (e.g. prior to the point in which the substrateencounters the laser source and/or prior to the material entering theelectrolyte source).

It will be understood that the foregoing is only illustrative of theprinciples of the disclosed subject matter, and that variousmodifications can be made by those skilled in the art without departingfrom the scope and spirit of the principles. Moreover, features ofembodiments described herein can be combined and/or rearranged to createnew embodiments.

1. A system for metal-plating and/or etching on a curved surface of asubstrate by action of a chemical solution in a tank containing thechemical solution, the substrate covered by an interfering surfacecoating, the system comprising: a substrate-holding fixture disposedrelative to the tank so that at least a portion of the curved surface ofthe substrate is submerged in the contained chemical solution; a lightbeam source adapted to emit a light beam, and one or more opticalelements that optically couple the light beam source to thesubstrate-holding fixture, the one or more optical elements configuredto direct the light beam in situ on the submerged portion of the curvedsurface of the substrate from multiple directions to remove theinterfering surface coating thereon and to expose the submerged portionof the curved surface to the action of the chemical solution, therebypermitting metal-plating and/or etching directly on the curved surfaceof the substrate without interference by the surface coating.
 2. Thesystem of claim 1, wherein the light beam is a pulsed laser.
 3. Thesystem of claim 1, wherein the pulsed laser is selected from the groupconsisting of a UV laser and a femtosecond laser.
 4. The system of claim2, wherein the one or more optical elements comprises an oscillatingoptical element that reflects or refracts the light beam so that thelight beam is incident upon the entire circumferential length of thecurved surface of the substrate.
 5. The system of claim 1, wherein theone or more optical elements comprises an optical fiber carrying thelight beam.
 6. The system of claim 1, wherein the curved surface is aninterior surface of the substrate, and wherein the system furthercomprises a mechanism to rotate and translate the substrate relative tothe light beam so that the light beam irradiation traverses the entirecircumferential length of the curved surface of the substrate.
 7. Thesystem of claim 6, wherein the mechanism to rotate and translate thesubstrate relative to the light beam comprises a mechanism to rotate andtranslate the substrate relative to the tank containing the chemicalsolution.
 8. A system for metal-plating and etching a two-dimensionalsurface of a substrate by action of a chemical solution in a tankcontaining the chemical solution, the substrate covered by aninterfering surface coating, the system comprising: a substrate-holdingfixture disposed relative to the tank so that at least a portion of thetwo-dimensional surface of the substrate is submerged in the containedchemical solution; a light beam source adapted to emit a light beam, andone or more optical elements that optically couple the light beam sourceto the substrate-holding fixture, the one or more optical elementsconfigured to direct the light beam in situ on the submerged portion ofthe two-dimensional surface of the substrate to remove the interferingsurface coating thereon and to expose the submerged portion of thetwo-dimensional surface to the action of the chemical solution, therebypermitting metal-plating and/or etching directly on the substratewithout interference by the surface coating.
 9. The system of claim 8,wherein the a one or more optical elements is configured to direct thelight beam along at least a length of the two-dimensional surface. 10.The system of claim 8, further comprising a substrate translationmechanism which moves the substrate along at least a length of itstwo-dimensional surface under light beam irradiation. 11-29. (canceled)30. A system for metal-plating or etching a substrate comprising: alaser; a first bath including a first chemical solution and a firstcounter electrode, and coupled to a first power supply utilizing aswitch for producing mechanical motion of said substrate; and a secondbath including a second chemical solution and said first counterelectrode and coupled to a second power supply.
 31. A system formetal-plating or etching a substrate comprising: a bath; and a scanningmirror coupled to a lens and a laser for ablating said substrate in saidbath to achieve said plating or etching.
 32. A system of claim 31,further comprising a reel-to-reel system to control the movement of saidsubstrate. 33-38. (canceled)
 39. A system for metal-plating or etching asubstrate comprising: a first bath; a supply tank for depositing a layerof chemical solution onto at least one surface of said substrate; and atleast one laser optically coupled to at least one lens for ablating saidsubstrate in said first bath to achieve plating or etching.
 40. Thesystem of claim 39, further comprising a reel-to-reel system to controlthe movement of said substrate.
 41. The system of claim 39, wherein saidat least one lens is at least one lens with a focal length greater than30 cm.
 42. The system of claim 39, further comprising a second bathseparated from said first bath by a first partition, said second bathcontaining an electrode for electroplating said substrate.
 43. Thesystem of claim 39, wherein said supply tank is said first bath.
 44. Thesystem of claim 39, further comprising a second partition, positionedadjacent to a wall of said first bath such that a channel is formed inwhich said layer of chemical solution is deposited onto at least twosurfaces of said substrate.
 45. The system of claim 39, furthercomprising of a plurality of mirrors for directing at least one laserbeam produced by said at least one laser to irradiate said substratefrom more than one angle. 46-50. (canceled)
 51. A system formetal-plating or etching a substrate from more than one anglesimultaneously comprising: a bath containing a chemical solution; one ormore lenses; one or more lasers coupled to a plurality of mirrors forirradiating said substrate at least partially immersed in said chemicalsolution in said bath from more than one angle simultaneously with laserbeams passed through said one or more lenses.
 52. A system for the insitu removal of an inhibiting film on a metal substrate comprising; asubstrate with an inhibiting film at least partially submerged in anelectrolyte; a laser radiation source directed toward the substrate, thelaser radiation selected from the group consisting of a UV laser and afemtosecond laser.
 53. The system of claim 52 wherein said UV radiationis in the wavelength range 157-356 nm.
 54. The system of claim 52 wheresaid femtosecond laser pulses are in the wavelength range of from about700 nm to about 1000 nm.
 55. The system as in claim 52 with a counterelectrode submerged in said electrolyte; a power supply connected tosaid substrate and counter electrode to commence with one of a groupconsisting of electroplating and electroecthing after removal of saidoxide film by said laser irradiation.
 56. The system of claim 52 whereinsaid substrate is removed from said electrolyte for one of plating andetching at a later time in any one of several suitable electrolytes.57-58. (canceled)
 59. A system for metal-plating and/or etching on acurved surface of a substrate by action of a chemical solution in a tankcontaining the chemical solution, the substrate covered by aninterfering surface coating, the system comprising: a light beam sourceadapted to emit a light beam, a substrate; one or more optical elementsthat optically couple the light beam source to at least a portion of thesubstrate, the one or more optical elements configured to direct thelight beam on the curved surface of the substrate from multipledirections to remove the interfering surface coating thereon; and asubstrate-holding fixture disposed relative to the tank so that at leasta portion of the curved surface of the substrate is submerged in thecontained chemical solution; wherein the tank is located in proximity tothe substrate coupled to the light beam source so as to permitmetal-plating and/or etching directly on the curved surface of thesubstrate prior to reformation of the interfering surface coating. 60.The system of claim 59, wherein the light beam is a pulsed laser. 61.The system of claim 60, wherein the pulsed laser is selected from thegroup consisting of a UV laser and a femtosecond laser.
 62. The systemof claim 59, wherein the substrate-holding fixture comprises a reel toreel system.
 63. The system of claim 62, wherein the reel to reel systemcomprises a steam source located so as to allow the steam to contact thesubstrate prior to being optically coupled to the light source.